Customized cutting for correcting ametropia

Abstract

The invention relates to a device, a computer program and a method for correcting ametropia of vision. In a first example, a position (480) of a desired focus point (440) relative to a retina of an individual eye may be determined based on obtained topographic information of an anterior corneal surface (401) and a posterior corneal surface (402) and refractive aberration information of the eye. In a second example, correction information (416, 496) related to the anterior corneal surface (401) may be determined based on the obtained topographic information of the anterior corneal surface (401) and posterior corneal surface (402) and based on the obtained topographic information of the anterior lens surface (431) and posterior lens surface (432) of the individual's eye to optimize focus onto the retina of the eye.

Description

Technical Field

[0001] The present invention relates to customized ablation for correcting refractive errors of vision, and more particularly, to the determination of a customized volume of corneal tissue to be ablated, corresponding devices, and computer programs. Background Art

[0002] Corneal refractive surgery has advanced significantly in the past two decades, giving rise to customized ablation, where the ablation profile is adapted to the specific needs of each patient to correct their refractive errors of vision.

[0003] When treating the eye cornea to correct refractive errors of vision, the refractive error (e.g., refractive aberration information) is typically first determined. In the prior art, the tissue volume equivalent to the lens required to correct the refractive aberration information is then calculated using the corneal refractive index to correct the patient's vision, and the cornea is treated by laser ablating the calculated lens for correcting refractive errors of vision.

[0004] In more recent prior art, several different methods have been introduced to determine the target profile of the anterior corneal surface, rather than calculating the tissue volume equivalent to the lens required to correct refractive aberration information. In one example, the target profile of the anterior corneal surface can be subjectively determined by the treating physician, i.e., the treating physician can determine the target profile based on their clinical experience such that it meets clinical requirements. WO 98 / 42291 relates to such a method. According to the available resolution, a set of points on the eye cornea and the position of each point are determined. Then, the computer determines the distance between the actual surface of the cornea and a predetermined reference surface for each point in the determined set of points. The predetermined reference surface can be determined based on clinical experience and / or alternative methods. Then, the determined distances define the profile for corneal tissue ablation.

[0005] In another example, refractive correction values can be determined for individual points on the patient's cornea. These refractive correction values can be determined by searching for diopter values that optimize the focusing of light rays impinging on the cornea generated by a light source arranged at an infinite distance at the fovea level (EP 1 352 623). Then, this set of refractive correction values defines the profile for corneal tissue ablation.

[0006] Additional prior art can be found in US 2015 / 131054 A1 and WO 2019 / 202104 A1.

[0007] However, the known methods only consider the structure of the individual eye to a limited extent. Correspondingly, the current methods for determining the corneal target profile are not always optimal in terms of improving visual quality. More importantly, the current methods may result in the amount of corneal tissue ablation being potentially (significantly) higher than the required amount.

[0008] Therefore, it is necessary to improve the determination of the corneal target profile so that corneal tissue ablation can be minimized and / or so that visual quality can be further improved. SUMMARY OF THE INVENTION

[0009] A first embodiment of the present invention relates to an apparatus for correcting visual refractive errors. The apparatus includes means for obtaining topographical information of the anterior surface of the cornea and topographical information of the posterior surface of the cornea of an individual's eye. The apparatus further includes means for obtaining distance information of the retina of the eye relative to the anterior surface of the cornea of the individual's eye. The apparatus also includes means for determining the position of a desired focal point relative to the retina based on the topographical information of the anterior surface and the posterior surface of the cornea and the refractive aberration information of the eye.

[0010] The basic idea of the present invention is that the main limitation of prior art methods is that these methods only consider the individual structures of the eye to a limited extent. Therefore, correcting visual refractive errors based on data in which individual eye information is only considered in a limited way is not optimal. However, obtaining more individual eye data would require reliable acquisition of this data, which is not always the case in the prior art.

[0011] According to this embodiment, a desired focal point, i.e., the point on which the eye should focus to optimize vision, is determined based on the refractive aberration information of the individual eye (e.g., measurement information, such as in a vision test performed by an ophthalmologist or in a wavefront analyzer or in a scanning laser refractometer measurement) and taking into account the topographical information (e.g., measurement information) related to the anterior surface and the posterior surface of the cornea of the individual eye. In a subsequent step, this desired focal point can then be used to determine the modifications that need to be made to the anterior surface of the cornea to optimize the vision of the individual eye.

[0012] Especially when dealing with complex cases, such as irregular astigmatism or dilation, the posterior surface of the eye's cornea may have associated irregularities. Correction based solely on the anterior surface of the cornea may not be satisfactory because, despite the applied correction, the (neglected) irregular posterior corneal shape may cause uncompensated refractive aberrations. Therefore, correcting visual refractive errors based solely on the topographical information of the anterior surface of the cornea may not be optimal. Since in a real eye, refraction occurs not only at the anterior surface of the cornea but also at the posterior surface of the cornea (due to the transition from the denser corneal stroma of the eye to the less dense aqueous humor of the eye), considering the posterior surface of the cornea of a specific patient (e.g., including information on the distance of the posterior surface of the cornea relative to the anterior surface of the cornea) can allow for a better determination of the correction information. This is especially the case because the posterior surface of the cornea can vary greatly from patient to patient and may have an irregular shape (which can usually be described not only by a linear function or a quadratic function but also by higher-order functions, such as third-order and higher-order functions, e.g., polynomials that may not have a shape approximable by a sphere or an ellipse, etc.).

[0013] However, the inventors of the present invention have recognized that the refractive error information and the topographical information of the corneal surface may not always be completely accurate, and / or individual patients may have, for example, lenses with irregular shapes, such that the above steps for determining the desired focal point do not always accurately determine the desired focal point. It is actually crucial to reliably obtain the contribution (e.g., of the posterior surface of the cornea) of each patient, just like the refractive aberration information.

[0014] Therefore, according to this embodiment, the component for obtaining the distance information of the retina of the eye relative to the anterior surface of the individual eye's cornea and determining the position of the desired focal point relative to the retina allows for providing a measure of reliability. Thus, more accurate data regarding the individual eye may be required for visual refractive error correction. By determining a measure of reliability (e.g., the distance of the desired focal point relative to the retina) based on the topographical information of the anterior surface and the posterior surface of the cornea and the refractive aberration information, it is possible to verify whether the obtained data is reliable.

[0015] The topographical information of the corneal surface (e.g., the anterior surface and / or the posterior surface) may include contours (e.g., a plurality of coordinates defining one or more actual points on the corneal surface, a plurality of points approximating the corneal surface, or a function fitted to the corneal surface, etc.). The topographical information can be provided, for example, in the form of a plurality of points in an x - y - z coordinate system. Of course, other coordinate systems can be used. Then, the correction information can be determined based on the topographical information of the anterior surface and the posterior surface of the cornea and the desired focal point.

[0016] It should be noted that the above device may not necessarily include components for determining or calculating topographical information and / or a desired focus point. The obtaining component may be implemented by a component for receiving corresponding information from other devices or device operators. In such instances, the device may directly use the received information to determine correction information and / or a desired focus point, and / or the device may further process the received information. For example, topographical information and / or a desired focus point related to a patient may be retrieved from a memory, a database, a server in the cloud, and / or from a corresponding diagnostic device, or these topographical information and / or a desired focus point may be input only by a device operator such as a surgeon.

[0017] The refractive aberration information may include the subjective refraction of the eye (such as one or more spherical diopter values and / or one or more cylindrical diopter values and one or more cylinder axes), for example, as obtained by a typical vision test. Thus, in some instances, the refractive aberration information includes or consists of subjective refraction. Additionally or alternatively, the device may include components for obtaining refractive aberration information of the eye from a scanning laser refractometer (such as that disclosed in EP 1 459 676) and / or a wavefront analyzer or similar device. For example, the refractive aberration information may include one or more parameters obtainable from a wavefront analyzer, such as polynomial coefficients. The scanning laser refractometer and / or the wavefront analyzer may be adapted, for example, to provide refractive aberration information in the form of a refractive error map for a selected area on the anterior corneal surface, as explained. For example, the refractive error may be represented as diopter values, coefficients of one or more polynomials such as Zernike polynomials, and so on. The device may include a scanning laser refractometer and / or a wavefront analyzer, or may merely import refractive aberration information from a laser refractometer and / or a wavefront analyzer through any medium. The refractive aberration information may also be obtained, for example, by a device operator who may input this information through an interface. Additionally or alternatively, the refractive aberration information may be obtained from a storage medium.

[0018] In some instances, the component for determining the position of the desired focus point may be further adapted to determine the position based on a lens model that estimates the lens of the eye (e.g., a statistical lens model that can describe average lens parameters based on data measured for a large number of eyes, for example). Thus, when determining the desired focus point, the (estimated) contribution of the lens to the refraction within the eye can also be considered. As described, by determining the desired focus point relative to the retina, the reliability of the lens model and / or the refractive aberration information can be analyzed. Based on the distance information measured for an individual eye, it can be verified whether the desired focus point is indeed located on or near the retina. For example, if the distance of the desired focus point relative to the (measured) retina (i.e., the reliability measure) is higher than a threshold, e.g., higher than 500 µm, more preferably higher than 300 µm, and most preferably higher than 100 µm, then the available data for the individual eye (e.g., refractive aberration information and / or the lens model that estimates the lens of the eye) can be determined to be incorrect.

[0019] If the deviation is too large, e.g., greater than the above threshold, it can be determined, for example, that the patient's lens does not conform to the lens model (and / or the refractive aberration information and / or topographic information related to the anterior corneal surface and / or posterior corneal surface are inaccurate).

[0020] The lens model of the eye can include, for example, a lens profile (e.g., an anterior lens profile and / or a posterior lens profile). The lens profile can include a plurality of coordinates that define one or more actual points on the anterior lens surface and / or the posterior lens surface, a plurality of points that approximate the anterior lens surface and / or the posterior lens surface, or a function that fits the anterior lens surface and / or the posterior lens surface, similar to what was described above for the topographic information of the corneal surface. The lens profile can additionally or alternatively include distance information, e.g., the distance of the anterior surface and / or the posterior surface of the lens model relative to the anterior corneal surface (e.g., statistical distance information that can describe the average distance by which the anterior surface and / or the posterior surface of the lens model are separated from the anterior corneal surface based on data measured for a large number of eyes).

[0021] In some instances, the parameters of the lens model can be adapted to an individual eye. For example, the parameters can be adjusted based on the distance information of the retina relative to the anterior corneal surface. However, the parameters of the lens model may not contain any measured parameters. Additionally or alternatively, they can or may not use wavefront measurements and / or use a fit to wavefront measurements to obtain.

[0022] In some instances, the device may further include a component for obtaining distance information. The distance information may include the distance of the anterior surface of the lens of the eye relative to the anterior surface of the cornea of the individual eye, and / or the distance of the posterior surface of the lens relative to the anterior surface of the cornea of the individual eye (e.g., information measured for the individual eye). The obtained distance information may be used to place a lens model that models the lens of the eye based on the distance information (e.g., via the anterior surface of the lens and / or the posterior surface of the lens). Thereby, the reliability metric, i.e., the distance of the desired focal point relative to the retina, may be further improved, allowing for a more accurate determination of whether the available individual eye data is accurate. This in turn allows for a more personalized correction of vision refractive errors when the available individual eye data is used for vision refractive error correction.

[0023] In some instances, the component for determining the position of the desired focal point relative to the retina may be further adapted to make the determination based on the lens profile of a lens model that models the lens of the eye. Thereby, in order to determine the distance of the desired focal point relative to the retina, not only the topographical information of the anterior surface and the posterior surface of the cornea, but also the model of the lens profile of the lens of the eye is considered. An even more improved reliability metric is thereby obtained, resulting in a more reliable result, e.g., a result regarding whether the obtained individual eye data is accurate.

[0024] In some instances, the device may be adapted to issue a warning in the case where the position of the desired focal point relative to the retina exceeds a predetermined threshold. Thereby, the device operator is warned that the available data may be incorrect and may reconsider the data before using the available data to correct vision refractive errors.

[0025] In some instances, the component for obtaining the desired focal point may be further adapted to determine the desired focal point by ray tracing of at least one ray refracted by an optical component corresponding to the correction of the refractive aberration information of the eye, based on the topographical information of the anterior surface and the posterior surface of the cornea (which may include the distance information of the posterior surface relative to the anterior surface). As is known to those skilled in the art, the refraction at the interface between two materials (e.g., air and corneal tissue, corneal tissue and aqueous humor, aqueous humor and lens, lens and vitreous humor, etc.) may be calculated, for example, based on Snell's law and the refractive indices of the two materials. Therefore, based on the topographical information (e.g., profile) of the corneal surface (which may include distance information) and the refractive indices of the relevant materials (known to those skilled in the art), the refraction of the rays passing through the anterior surface and the posterior surface of the cornea and possibly also through the anterior surface and the posterior surface of the lens may be calculated.

[0026] Using ray tracing as mentioned in the previous paragraph, the available eye data can be verified by tracing one or more rays. The rays can be incident on an optical component (such as a lens corresponding to the correction of refractive aberration information of the eye) corresponding to the correction of the refractive aberration information of the eye in a manner parallel to the optical axis of the eye. Before the rays intersect the internal optical axis of the eye, the rays are refracted by the optical component, the anterior corneal surface and the posterior corneal surface, and possibly also by a lens model (which may be placed according to distance information and may also be described by the profile of the anterior surface and / or the posterior surface). The intersection point (such as its centroid) of the rays with the internal optical axis of the eye can define the desired focal point, and based on the desired focal point, the distance relative to the retina can be determined.

[0027] In some instances, an area within a specific radius around the corneal vertex (or the center of the anterior corneal surface) can be considered for ray tracing. For example, an area on the anterior surface within a diameter corresponding to the pupil diameter of the eye can be considered, where the pupil diameter is detected according to a predefined light environment, preferably but not necessarily obtained by a pupillometer. Then, for a regular or randomized point grid within such an area, ray tracing can be performed such that for each point, the position of the desired focal point relative to the retina can be obtained as described in the previous paragraph. By using an appropriate number of points, an estimate of the desired focal point relative to the retina can be obtained, for example, by calculating the centroid or taking a weighted average of the determined positions.

[0028] In some instances, ray tracing involves at least one first ray incident on the optical component in a manner parallel to the optical axis of the eye (forward ray tracing). For example, forward ray tracing can be performed for multiple first rays, with each first ray incident on a corresponding point of a point grid within a selected area on the anterior corneal surface, as outlined in the previous paragraphs.

[0029] In the case of forward ray tracing, the position of the desired focal point relative to the retina can be defined as the intersection point of at least one first ray with the optical axis of the eye after being refracted by the optical component, the anterior corneal surface and the posterior corneal surface, and possibly also by a lens model (which may be placed according to distance information and may also be described by the profile of the anterior surface and / or the posterior surface). By making this determination for multiple rays, where each ray is incident on a point of the point grid on the anterior surface, the desired focal point can be obtained by taking, for example, a weighted average of the relative distances between the intersection points of the rays with the optical axis and the retina. Thus, a reliable estimate of the desired focal point can be determined.

[0030] In some instances, in addition to or instead of forward ray tracing, ray tracing may also involve at least one second ray exiting from a desired focus point (backward ray tracing). For example, backward ray tracing may be performed for multiple second rays, each second ray exiting the optical component (e.g., a lens corresponding to the correction of refractive aberration information) corresponding to the correction of the refractive aberration information of the eye, the posterior surface of the cornea and the anterior surface of the cornea, and possibly also refracted by a lens model (placed according to distance information and possibly also described by the profiles of the anterior and posterior surfaces) after being refracted by the optical component.

[0031] In the case of backward ray tracing, the desired focus point may be at least partially determined (e.g., iteratively) such that the angle between the eye's optical axis and at least one second ray is minimized when the at least one second ray exits the optical component after being refracted by the lens model (placed according to distance information and possibly also described by the profiles of the anterior and posterior surfaces), the posterior surface of the cornea and the anterior surface of the cornea (determined by the corresponding topographic information), and the optical component (e.g., a lens simulating the correction corresponding to the refractive aberration information). For example, the desired focus point may be determined such that the angle between the ray traced ray exiting the optical component and the optical axis is substantially zero. In a manner similar to that described above, this may be done for a set of points on the anterior surface of the cornea.

[0032] In some instances, the device may further include a component for determining correction information related to the anterior surface of the cornea based on the topographic information of the anterior surface and the posterior surface of the cornea to optimize the focusing onto the desired focus point. In some instances, the focusing may also be optimized based on the distance information between the anterior surface and the posterior surface of the cornea and / or the lens model and / or the distance information of the lens model.

[0033] The correction information may include the correction to be applied to the anterior surface of the cornea, such that the rays refracted by the corrected anterior surface and the posterior surface are optimally focused onto the desired focus point. For example, the correction information may define the correction in the form of a cutting volume, a cutting profile, and / or a target profile and / or a target slope of the anterior surface of the cornea. The correction information may contain values related to the individual points on the anterior surface of the cornea, such as a grid of points on the anterior surface of the cornea. The correction information may then be used to cut the corresponding corneal volume.

[0034] In some instances, the correction information may include a target slope and / or a target profile of the anterior corneal surface. For example, the correction information may relate to one or more points (e.g., forming a grid) on the anterior corneal surface, where for each point, a target slope or a target thickness may be indicated, e.g., in the form of a map or a profile of the target anterior corneal surface. However, the correction information may also relate to the value to be ablated, such as a target ablation volume and / or a target ablation thickness (for each point). The target ablation value may be obtained by intersecting the topographical information of the anterior corneal surface with, for example, a target profile of the anterior corneal surface that optimizes vision.

[0035] Using ray tracing as mentioned in the previous paragraphs, the correction information can be determined at least in part to optimize the focusing at a desired focal point. In other words, the correction to be applied to a specific point on the anterior corneal surface is determined such that the light rays passing through said point are optimally focused onto the desired focal point, as calculated based on the (corrected) anterior surface configuration and based on the topographical information of the posterior corneal surface and possibly based on the distance information between the anterior corneal surface and the posterior corneal surface and / or the lens model and / or the distance information of the lens model.

[0036] In some instances, in a manner similar to that described above, an area within a specific radius around the corneal vertex (or the center of the anterior corneal surface) may be considered for ray tracing. For example, in a manner similar to that described above, an area on the anterior surface within a diameter corresponding to the pupil diameter of the eye, which is detected according to a predefined light environment, preferably but not necessarily obtained by a pupillometer, may be considered. Then, for a regular or randomized point grid within such an area, ray tracing may be performed such that for each point, the corresponding correction information, such as the target slope of the anterior surface at said point, can be obtained. By using an appropriate number of points, the correction information can be determined in the form of a map of the anterior corneal surface.

[0037] In some instances, ray tracing involves forward ray tracing, where at least one first ray is incident on the anterior corneal surface in a direction parallel to the optical axis of the eye. Forward ray tracing may be performed for a plurality of first rays, each first ray being incident on a corresponding point of a point grid within a selected area of the anterior corneal surface, as outlined above.

[0038] In the case of forward ray tracing, correction information related to the anterior corneal surface can be at least partially determined to optimize focusing at a desired focal point, i.e., to make the point at which the light is focused as close as possible to the desired focal point. The point at which the light is focused can be defined as the intersection point of the light ray, after being refracted by the anterior corneal surface and the posterior corneal surface (possibly taking into account the distance information between the anterior and posterior corneal surfaces) and possibly also by a lens model (possibly placed according to distance information and possibly also described by the profiles of the anterior and posterior surfaces), with the optical axis of the eye. For example, the target slope of the anterior corneal surface can be determined such that the distance between the desired focal point and the aforementioned intersection point is substantially zero. By performing this determination for multiple light rays, where each light ray impinges on one point of a point grid on the anterior surface, the necessary correction information to be applied at that point can be determined such that each light ray impinging on the corresponding point is optimally focused to the desired focal point. Thus, correction information for the entire point grid, such as the target slope, can be obtained. Then, the target profile of the anterior corneal surface can be determined, for example, by integrating the determined target slopes.

[0039] In some instances, in addition to or instead of forward ray tracing, ray tracing can also involve at least one second ray exiting from the desired focal point (backward ray tracing), as described above. In a manner similar to that described above, backward ray tracing can be performed for multiple second rays, each second ray leaving the cornea at a corresponding point of a point grid within a selected region of the anterior corneal surface after being refracted by the posterior corneal surface and the anterior corneal surface (possibly taking into account the distance information between the anterior and posterior corneal surfaces) and possibly also by a lens model (possibly placed according to distance information and possibly also described by the profiles of the anterior and posterior surfaces).

[0040] In the case of backward ray tracing, correction information related to the anterior corneal surface can be at least partially determined to minimize the angle between the optical axis of the eye and at least one second ray when the at least one second ray exits the cornea after being refracted by a lens model (possibly placed according to distance information and possibly also described by the profiles of the anterior and posterior surfaces), the posterior corneal surface, and the anterior corneal surface (determined by the corresponding topographical information) and possibly taking into account the distance information between the anterior and posterior corneal surfaces. For example, correction information can be determined such that the angle between the ray traced ray exiting the cornea and the optical axis is substantially zero. In the same way, for a point grid on the anterior corneal surface, the necessary correction information can be determined such that for each point of the grid, the angle between the ray traced ray exiting the cornea and the optical axis is substantially zero.

[0041] Another (second) embodiment of the present invention relates to a device for correcting visual refractive errors. The device includes: a component for obtaining topographical information of the anterior surface of the cornea and topographical information of the posterior surface of the cornea of an individual's eye; a component for obtaining topographical information of the anterior surface of the lens and / or topographical information of the posterior surface of the lens of an individual's eye; and a component for obtaining distance information of the retina of the eye relative to the anterior surface of the cornea of the individual's eye. The device further includes a component for determining correction information related to the anterior surface of the cornea based on the topographical information of the anterior surface and the posterior surface of the cornea and the topographical information of the anterior surface and the posterior surface of the lens to optimize focusing onto the retina of the eye.

[0042] It should be noted that the first embodiment and the second embodiment and all aspects related to these embodiments described herein can be combined. For example, a single device implementing both embodiments can be provided. Unless explicitly outlined to the contrary, the aspects described with reference to the first embodiment also apply to the second embodiment, and vice versa.

[0043] Taking into account the topographical information of the anterior surface and the posterior surface of the lens of an individual's eye when determining the correction information - rather than only considering the anterior surface and the posterior surface of the cornea of the individual's eye - allows obtaining a cutting volume that is more suitable for the needs of each patient and improving visual correction, because the refractive contribution of the lens can be considered.

[0044] As outlined above, the basic idea of the present invention is that the main limitation of the prior art methods is that they only consider the individual structures of the eye to a limited extent. The prior art methods ignore the refractive contribution of the lens of the eye, or only consider this to a very limited extent. For example, in the case of abnormal lens shape, the correction calculated only based on the surface information of the cornea and / or the regular shape of a general lens model may not be satisfactory, because despite the application of the correction, the (ignored) abnormal shape of the individual lens may cause refractive aberrations. Therefore, this correction is not optimal. Considering the cornea and lens shapes of a specific patient allows for better determination of the correction information. Therefore, the visual correction of each patient can be improved. This is especially the case because the corneal surface and the lens surface can vary greatly from patient to patient and may have irregular shapes (which can usually be described not only by linear functions or quadratic functions, but also by higher-order functions, such as third-order and higher-order functions, such as polynomials that may not have a shape approximable by a sphere or an ellipse, etc.). Taking into account the specific configuration (morphology or shape) of the eye cornea and lens when determining the correction information for optimizing focusing onto the retina of the eye allows eliminating this problem. Considering not only the refractive contribution of the corneal surface but also the refractive contribution of the lens of each patient allows for optimizing the correction and often minimizing the cutting volume necessary for the correction.

[0045] In a manner similar to that already described above, the device may not necessarily include components for determining or calculating topographical information and / or distance information of the retina of the eye. The obtaining component may be implemented by a component for receiving the corresponding information from other devices or the device operator. In such instances, the device may directly use the received information to determine the correction information and / or the retina, and / or the device may further process the received information. For example, the topographical information and / or distance information of the retina of the eye relative to the anterior corneal surface related to the patient may be retrieved from a memory, a database, a server in the cloud, and / or a corresponding diagnostic device, or this information may simply be input by the device operator, such as a surgeon.

[0046] In one example, the topographical information of the anterior surface of the lens of the eye and the topographical information of the posterior surface of the lens may be obtained for near vision and / or distance vision. As described above, the topographical information of the lens may include a contour. In some examples, this contour may be obtained for distance vision and / or near vision. This contour may also be obtained for a radius corresponding to the pupil diameter of the eye and detected according to a predefined light environment (e.g., for distance vision), or a smaller radius may be considered (e.g., for near vision). In some examples, a radius around the corneal apex (or the center of the anterior corneal surface) may be considered, preferably obtained by a pupillometer. It is noted that in the case of pupil data detected by a pupillometer, in this regard, the pupillometer does not need to be part of the device, but it is sufficient if the device is adapted to receive the corresponding pupil data, for example, from a storage device or through a corresponding interface from the device operator. For example, the correction information may be determined separately in each zone determined within the area within the pupil radius of the eye for near vision and distance vision. Thus, the correction information may include correction information specific to one or more zones for near vision and distance vision.

[0047] In some examples, the component for determining the correction information may be adapted to perform ray tracing for at least one ray that passes through the cornea and is refracted by the anterior and posterior corneal surfaces and passes through the lens and is refracted by the anterior and posterior lens surfaces, based on the topographical information of the anterior and posterior corneal surfaces and the topographical information of the anterior and posterior lens surfaces, to optimize the focusing on the retina. The same considerations as those described above regarding ray tracing also apply here.

[0048] In some examples, the device may further include means for obtaining distance information of the posterior surface of the cornea of an individual's eye relative to the anterior surface of the cornea and / or the distance of the anterior surface of the lens of the eye relative to the anterior surface of the cornea of the individual's eye and / or the distance of the posterior surface of the lens of the eye relative to the anterior surface of the cornea of the individual's eye. The means for determining correction information related to the anterior surface of the cornea to optimize focusing onto the retina of the eye may further be adapted to perform the determination based on at least one obtained distance information. Using the obtained distance information in addition to the topographical information (such as profiles) of the corneal surface, lens surface and the refractive indices of the relevant materials (known to the person skilled in the art) would allow for a further improvement of, for example, the ray tracing described above. The distance information may also be used in the ray tracing process outlined in the previous paragraph.

[0049] In one example, a device according to the first and / or second embodiment may be adapted to obtain topographical information of the anterior surface and the posterior surface of the cornea of an eye from a corneal tomograph. The tomograph may be based on light scattering techniques and / or ultrasonic techniques and the like. Additionally or alternatively, optical coherence tomography techniques may be used.

[0050] In another example, the device may further be adapted to obtain topographical information of the anterior surface and the posterior surface of the lens, for example from optical coherence tomography techniques or ultrasonic techniques.

[0051] In another example, the device may be adapted to obtain from a biometer distance information of the posterior surface of the cornea of an individual's eye relative to the anterior surface of the cornea and / or the distance of the anterior surface of the lens of the eye relative to the anterior surface of the cornea of the individual's eye and / or the distance of the posterior surface of the lens of the eye relative to the anterior surface of the cornea of the individual's eye. The biometer may be based on ultrasonic techniques or optical coherence tomography techniques.

[0052] In another example, the topographical information of the anterior corneal surface and the posterior corneal surface obtained from a corneal tomographer and the topographical information of the anterior lens surface and the posterior lens surface obtained from an optical coherence tomographer can be used for ray tracing as described herein. For example, determining the correction to be applied to a particular point (obtained from the corneal tomographer) on the anterior corneal surface such that light rays passing through said point are optimally focused onto the retina, as calculated based on the (corrected) anterior surface configuration and based on the topographical information of the posterior surface (obtained from the corneal tomographer) and the topographical information of the anterior lens surface and the posterior lens surface (obtained from the optical coherence tomographer). In some examples, this can be done without any fitting parameters. In some examples, only the topographical information of the anterior corneal surface and the posterior corneal surface (obtained from the corneal tomographer) and the topographical information of the anterior lens surface and the posterior lens surface (obtained from the optical coherence tomographer) may be used. In some examples, distance information obtained from a biometer (such as an optical biometer) can also be used for ray tracing.

[0053] The device may include a tomographer. For example, in contrast to a Placido-ring based corneal tomographer, the use of a corneal tomographer allows not only the determination of the anterior corneal surface characteristics, but also the determination of characteristics regarding the corneal thickness, especially regarding the posterior corneal surface. For example, a corneal tomographer can provide topographical information such as the profiles of the anterior corneal surface and the posterior corneal surface. It can also provide thickness information about the cornea. It can also provide more detailed information about the corneal layers, such as the corneal epithelium and / or the corneal stroma. In some examples, as mentioned, when determining the correction information, the topographical information about the corneal layers can also be considered, which can allow for a more precise determination of the target anterior corneal surface to optimize vision.

[0054] In another example, the device may be adapted to obtain topographical information at least in part from a pupillometer to determine the (photopic) diameter of the eye pupil. The device may include such a pupillometer. The pupillometer can also be used to define the smallest area in the anterior corneal surface where refractive errors of vision can be corrected, the diameter of said area being determined according to a predefined light environment. In some examples, said area can also be subjectively determined and received by the device. Alternatively, the operator may preselect the eye area to be treated, and then in a next step, the information provided by the pupillometer, such as by using the pupil diameter, can be used to refine the preselected area. Overall, this allows for a precise limitation of the corneal area to be treated by laser surgery. Thus, the invasiveness of the surgical treatment may be reduced.

[0055] In another example, the device may further include a component for correcting eye aberrations based on the determined correction information, preferably a laser for removing corneal tissue. For example, an excimer laser or a solid-state laser may be used for this purpose. In other examples, the device may be adapted to determine correction information such that it can be provided to a laser for removing corneal tissue, but the laser is not necessarily part of the device.

[0056] In some examples, the device may be adapted to control a component for correction with closed-loop feedback. For example, the device may include a component for controlling a laser (or more generally: a correction component) based on the updated topographical information of the anterior corneal surface. During laser ablation, the topographical information of the anterior corneal surface can be updated, for example, in real time, and the ablation can be controlled accordingly, for example, in a closed loop. For example, if sufficient agreement is achieved between the updated topographical information and the correction information of, for example, the target profile of the anterior corneal surface, the ablation can be stopped, while the ablation can be controlled to continue as long as the agreement has not been achieved.

[0057] The device may also be adapted to store the determined correction information, for example, on a memory, in a database or on a server. Subsequently, the correction information can be retrieved by a component for correcting eye aberrations, such as a laser, which may be part of the device or may be provided separately.

[0058] In one example, a corneal tomograph, an optical coherence tomograph, a biometer, a scanning laser refractometer and / or a wavefront analyzer, a laser and optionally a pupillometer may be included in the device such that they become part of the device. In such examples, the device may include a processing and / or control unit (such as a computer) that interacts with the other mentioned parts of the device. For example, topographical information and / or refractive aberration information can be transmitted to the processing and / or control unit, for example, via one or more wires and / or wirelessly. For example, correction information can be transmitted from the processing and / or control unit to the laser in a similar manner. In another example, the individual mentioned parts may not necessarily be part of the device, thereby providing modular equipment. In this example, the device (which may still include a processing unit) may be adapted to exchange topographical information, refractive aberration information and / or correction information, for example, via one or more wires and / or wirelessly. For example, the corresponding information can be transmitted wirelessly to and from the device.

[0059] It should be noted that aspects related to determining a desired focus point relative to the retina can be combined with other aspects of the present invention, but can also be implemented independently of these other aspects. For example, methods and / or devices for obtaining topographical information of the anterior corneal surface and the posterior corneal surface of an eye can be provided. In addition, refractive aberration information of the eye can be obtained. The desired focus can be determined, for example, by ray tracing, based on the topographical information of the anterior corneal surface and the posterior corneal surface and based on the refractive aberration information.

[0060] Another embodiment of the present invention relates to a computer program comprising instructions for performing the steps described herein and / or implementing the components described herein. For example, the computer program can be stored on a memory medium and can cause a processor to implement the various steps. The memory medium and / or the processor can be included in a device according to the present invention. The device of the present invention generally can include the computer program of the present invention.

[0061] Another embodiment of the present invention relates to a method for correcting visual refractive errors. The method can include the step of obtaining topographical information of the anterior corneal surface and the posterior corneal surface of an eye. The method can further include the step of obtaining a desired focus point within the eye. The method can further include determining correction information related to the anterior corneal surface based on the topographical information of the anterior corneal surface and the posterior corneal surface to optimize focusing onto the desired focus point. The method may also optionally include other steps, which are described herein with reference to the device and / or the computer program. The method may not include the step of actually correcting the eye aberration based on the determined correction information. BRIEF DESCRIPTION OF THE DRAWINGS

[0062] Possible embodiments of the present invention will be described in more detail with reference to the following figures in the subsequent detailed description: Figure 1 : Exemplary flowchart for customizing corneal ablation according to an example of the present invention; Figure 2a : Schematic illustration of an exemplary corneal cross-section including the anterior corneal surface of the eye and a target anterior corneal surface; Figure 2b : Top view of an exemplary area of the anterior corneal surface that can be surgically treated, including a monofocal refractive zone and a custom connection zone.

[0063] Figure 2c : Top view of an exemplary area of the cornea to be surgically treated, including a multifocal refractive zone subdivided into a near vision zone, an intermediate vision zone, and a far vision zone, and a custom connection zone surrounding the multifocal zone.

[0064] Figure 3: Schematic illustration of an exemplary corneal cross-section with a lens cross-section, wherein the corneal cross-section includes the anterior corneal surface, the posterior corneal surface, and the slopes of points on the anterior and posterior corneal surfaces, and the lens cross-section includes the anterior lens surface and the posterior lens surface and the slopes of points on the anterior and posterior lens surfaces.

[0065] Figure 4a : Example for determining a region of the anterior corneal surface related to vision based on topographical information of the anterior and posterior corneal surfaces and based on a pre-defined, preferably the diameter of the clear pupil.

[0066] Figure 4b : Example for determining a desired focal point based on topographical information of the anterior and posterior corneal surfaces, topographical information of the anterior and posterior surfaces of a lens model estimating the lens of the eye, distance information of the posterior corneal surface relative to the anterior corneal surface, distance information of the anterior surface of the lens model relative to the anterior corneal surface, distance information of the posterior surface of the lens model relative to the anterior corneal surface, distance information of the retinal surface relative to the anterior corneal surface, and based on refractive aberration information.

[0067] Figure 4c : Example for determining a region of the anterior corneal surface, wherein correction information will be calculated based on topographical information of the anterior and posterior corneal surfaces, topographical information of the anterior and posterior surfaces of a lens model estimating the lens of the eye, distance information of the posterior corneal surface relative to the anterior corneal surface, distance information of the anterior surface of the lens model relative to the anterior corneal surface, distance information of the posterior surface of the lens model relative to the anterior corneal surface, distance information of the retinal surface relative to the anterior corneal surface, based on the desired focal point and based on the diameter of the eye pupil detected according to a pre-defined light environment.

[0068] Figure 5a : First example for determining correction information by reverse ray tracing based on topographical information of the anterior and posterior corneal surfaces, topographical information of the anterior and posterior surfaces of a lens model estimating the lens of the eye, distance information of the posterior corneal surface relative to the anterior corneal surface, distance information of the anterior surface of the lens model relative to the anterior corneal surface, distance information of the posterior surface of the lens model relative to the anterior corneal surface, distance information of the retinal surface relative to the anterior corneal surface, and based on the desired focal point.

[0069] Figure 5b: A second example for determining correction information based on the topographic information of the anterior and posterior corneal surfaces, the topographic information of the anterior and posterior surfaces of the lens of the eye, the distance information of the posterior corneal surface relative to the anterior corneal surface, the distance information of the anterior surface of the lens model relative to the anterior corneal surface, the distance information of the posterior surface of the lens model relative to the anterior corneal surface, the distance information of the retinal surface relative to the anterior corneal surface, and by forward ray tracing based on a desired focal point.

[0070] Figure 5c : Having an exemplary cross-section of the cornea with an anterior corneal surface target profile obtained from an example according to Figure 5a and 5b of the example.

[0071] Figure 6a : A first example for determining correction information based on the topographic information of the anterior and posterior corneal surfaces, the topographic information of the anterior and posterior surfaces of the lens of the eye, the distance information of the posterior corneal surface relative to the anterior corneal surface, the distance information of the anterior surface of the lens relative to the anterior corneal surface, the distance information of the posterior surface of the lens relative to the anterior corneal surface, the distance information of the retinal surface relative to the anterior corneal surface, and by backward ray tracing based on the retina.

[0072] Figure 6b : A second example for determining correction information based on the topographic information of the anterior and posterior corneal surfaces, the topographic information of the anterior and posterior surfaces of the lens of the eye, the distance information of the posterior corneal surface relative to the anterior corneal surface, the distance information of the anterior surface of the lens relative to the anterior corneal surface, the distance information of the posterior surface of the lens relative to the anterior corneal surface, the distance information of the retinal surface relative to the anterior corneal surface, and by forward ray tracing based on the retina.

[0073] Figure 6c : Having an exemplary cross-section of the cornea with an anterior corneal surface target profile obtained from an example according to Figure 6a of the example. Detailed Description

[0074] Possible embodiments of the present invention will be described below. For the sake of brevity, only a few embodiments may be described. Those skilled in the art will recognize that the specific features described with reference to these embodiments can be modified and combined differently, and if a single feature is not necessary, it can also be omitted. The general explanations in the above sections also apply to the following more detailed explanations.

[0075] Figure 1 An example flowchart 100 showing customized corneal ablation performed with a device according to the present invention is shown.

[0076] In this example, a device includes a corneal topographer 101, a control unit 105 (such as a computer, such as a central control unit), a biometer 108, and an excimer or solid-state laser 106. The reference numeral 102 represents an operator, such as a treating physician. In this example, the device may optionally include a pupillometer 103 and / or a scanning laser refractometer and / or a wavefront analyzer 104 and / or a database 109, and / or an optical coherence tomographer (OCT) and / or an ultrasound scanning system 107.

[0077] The corneal topographer 101 may be adapted to provide topographical information of the anterior corneal surface and the posterior corneal surface. For example, the topographer may be based on light scattering techniques, ultrasonic techniques, and / or optical coherence tomography. The provided topographical information may include the profiles of the anterior corneal surface and the posterior corneal surface and possibly also slope profiles and / or curvature profiles. It may also provide thickness information about the cornea and / or more detailed information about the corneal layers, such as the corneal epithelium and / or the corneal stroma.

[0078] At reference numeral 102, refractive aberration information of the eye may be obtained by the device from an operator (such as a treating physician). This information may be, for example, refractive aberration information that can be subjectively determined by the operator based on their clinical experience. For example, the correction information may include spherical refractive correction, cylindrical refractive correction, and the associated axis, etc., which can be determined by a conventional visual acuity test or a schiascopic examination or an autorefractor.

[0079] In addition to or in place of the refractive aberration information obtained from the operator, such information may also be obtained from the scanning laser refractometer and / or the wavefront analyzer 104. The scanning laser refractometer and / or the wavefront analyzer may provide refractive aberration information, such as a refractive error map of a corneal cross-section and / or a two-dimensional area of the corneal surface. For example, the refractive error may be represented as an angular error or an angular slope or any other suitable form. The refractive error may be related to the error varying with the planar x and y (or any other) coordinates of the anterior corneal surface.

[0080] The optical corneal tomographer (OCT) and / or the ultrasound scanning system 107 may be adapted to provide topographical information of the anterior lens surface and the posterior lens surface of the eye. As described above for the anterior corneal surface and the posterior corneal surface, the provided topographical information may include the profiles of the anterior lens surface and the posterior lens surface of the eye and possibly also slope profiles and / or curvature profiles. It may also provide thickness information about the lens.

[0081] The biometer 108 may be adapted to provide distance information of the posterior surface of the cornea of ​​the eye relative to the anterior surface of the cornea and / or distance information of the anterior surface of the lens of the eye relative to the anterior surface of the cornea, and / or distance information of the posterior surface of the lens of the eye relative to the anterior surface of the cornea, and / or distance information of the retina of the eye relative to the anterior surface of the cornea. The biometer may be based on ultrasound biometry or optical biometry (e.g. using partial coherence interferometry). The distance information may be represented, for example, as a function of planar x and y (or any other) coordinates of the anterior surface of the cornea.

[0082] The pupil meter 103 can be used to determine, for example, the photopic pupil diameter, for example the pupil diameter ultimately associated with the statistical probability of the occurrence of a set of predefined light environments detected. The photopic pupil diameter can be preferably, but not mandatory, used to define the desired focal point, and the pupil diameter ultimately associated with the statistical probability of the occurrence of a set of predefined light environments detected can be preferably, but not mandatory, used to limit the corneal area to be treated by surgery. The corneal area corresponding to the photopic pupil diameter and to the pupil diameter ultimately associated with the statistical probability of the occurrence of the light environment detected according to a set of predefined light environments is determined by a ray tracing process. For example, this can allow the operator to better refine the preselected area of ​​the cornea for treatment. In addition, it can be determined which area of ​​the cornea should be used to determine the desired focal point (for example, by ray tracing). For the above determination, it may be useful if the determination of the iris plane makes it possible to more accurately calculate the projection of the pupil diameter onto the front surface (i.e., calculated separately for the patient's eye geometry). For this purpose, the device and / or the corneal tomograph may comprise means for determining the iris plane and / or means for obtaining such information. Alternatively, such a corneal region may be arbitrarily selected by the operator.

[0083] The database 109 can be used, for example, to model the lens of an individual eye. The database 109 can include profiles of a plurality of front and rear surfaces of different lenses and possibly also slope profiles and / or curvature profiles. The lens information can be related to data measured from different individuals, and / or they can be related to a generic model. Also, thickness information and / or distance information about the front surface of the cornea of ​​different lenses can be obtained in the database. Alternatively, the lens model can be arbitrarily selected by the operator.

[0084] The control unit 105 may be adapted to obtain information about the optical axis of the eye. The optical axis may be determined by the control unit 105, for example based on information provided by the tomograph or predefined by an operator. It may also be determined by the tomograph 101 and obtained by the control unit 105 from the tomograph 101. However, it may also be determined by other means and input to the control unit 105, for example by an operator. For example, the optical axis may be chosen to be the (approximately) symmetry axis of the cornea.

[0085] Similarly, the control unit 105 may be adapted to obtain information about the corneal visual centre, where the optical axis may be centered. This may correspond to the corneal vertex. The visual centre may be determined by the control unit 105, for example based on information provided by the tomograph or predefined by the operator. It may also be determined by the tomograph 101, for example based on the corneal vertex or based on the light gaze reflection on the anterior surface of the cornea or based on the corneal symmetry axis and obtained by the control unit 105 from the tomograph 101. However, it may also be determined by other means and input to the control unit 105, for example by an operator.

[0086] Topographic information obtained, for example, from a corneal tomograph 101, an optical coherence tomography (OCT) and / or an ultrasound scanning system 107 and / or from a database 109 and / or distance information obtained from a biometer 108 and / or pupil information that may be collected from a pupillometer 103 and / or refractive aberration information obtained, for example, from an operator 102 and possibly by a scanning laser refractor and / or by a wavefront analyzer 104 may be obtained by a control unit 105 of the device. The control unit 105 may then determine the corrective information based on the information obtained. The control unit may be adapted to determine the corrective information as generally described in the above section "Summary of the Invention" and as further described below with respect to FIGS. 2-6. In some instances, other characteristics of the eye of each patient may also be taken into account when determining the corrective information, such as topographic information about the retina and / or the fovea relative to the cornea. The corrective information may, for example, be expressed in terms of a customized ablation volume of corneal tissue. For example, the correction information may be related to the ablation depth, which is expressed in microns and varies with the planar x and y (or any other) coordinates of the anterior corneal surface. The topographic information of the anterior corneal surface and the posterior corneal surface may be related to similar coordinates. Figures 4a-4c , Figures 5a-5c and Figures 6a-6b Further exemplary details regarding the correction information determination are provided.The control unit 105 may further be adapted to control and coordinate other elements of the device with each other.

[0087] The determined correction information can then be provided to, for example, an excimer or solid state laser 106, which can ablate corneal tissue by using, for example, a series of deliberately set "laser pulses". The laser 106 can include a coupling interface for reading the correction information from the control unit 105. After performing one or more "laser pulses", the resulting anterior corneal shape can be examined, at least in part based on the correction information, for example by topography (or morphology) and / or refractometry. In one example, the corneal tomograph 101 can provide updated topographical information of the anterior corneal surface after ablation. In another example, the scanning laser refractometer and / or wavefront analyzer 104 can additionally or alternatively provide updated aberration information after ablation. This updated topographical information and / or aberration information can then be used to determine whether the target anterior corneal surface has been obtained. If the desired anterior surface or refractive error elimination has not been achieved after performing the entire ablation, the control unit 105 can determine another volume for corneal tissue ablation, which can then be removed by the excimer or solid state laser 106. Instead of applying such feedback after completing the entire ablation, it can also be applied in real time, or after ablating a particular portion of the entire planned ablation, for example such that possible calibration errors of the laser can be taken into account. If the target profile of the anterior corneal surface is obtained, the customized ablation procedure can be stopped.

[0088] In one example, the control unit 105 can represent an embodiment of the device of the present invention. In other examples, the corneal tomograph 101 and / or optical coherence tomograph (OCT) and / or ultrasound scanning system 107 and / or biometer 108 and / or laser 106 may or may not be part of the device. The control unit 105 may be adapted to interface with the corneal tomograph 101 and / or optical coherence tomograph (OCT) and / or ultrasound scanning system 107 and / or biometer 108 and / or laser 106. This can allow data to be received from the corneal tomograph 101 and / or optical coherence tomograph (OCT) and / or ultrasound scanning system 107 and / or biometer 108 and / or laser 106, and / or the laser 106 to be controlled.

[0089] In some instances, the control unit 105 may optionally be permanently (e.g., in a wired or wireless manner) coupled to any one of the corneal topographer 101 and / or optical coherence tomographer (OCT) and / or ultrasound scanning system 107 and / or biometer 108 and / or laser 106. However, this is not necessary. In other instances, the control unit 105, the corneal topographer 101 and / or the optical coherence tomographer (OCT) and / or the ultrasound scanning system 107 and / or the biometer 108 and / or the laser 106 may exchange data (unidirectionally, and / or bidirectionally in each direction) via a temporary coupling or via a data carrier (e.g., a USB device that is moved from one device to another, a server that they can access jointly, and / or any other available data carrier).

[0090] Figure 2a Schematic diagram showing a corneal cross-section 200a. This schematic illustration depicts, for example, topographical information of the anterior corneal surface measured by using a corneal topographer, i.e., profile 201a. In addition, a target profile 202a of the anterior corneal surface is depicted. The volume defined by the actual profile 201a and the target profile 202a of the anterior corneal surface defines, for example, the corneal tissue volume that can be ablated by an excimer or solid-state laser, i.e., the target ablation volume.

[0091] Figure 2b Schematic diagram showing a top view of a corneal region 200b where analysis and / or treatment can be performed. The region includes a monofocal zone 201b. The monofocal zone 201b may define a corneal region where treatment can be performed such that the visual quality at a distance is optimized. In one example, the monofocal zone may be determined by the treating physician and / or as explained by the pupillometer 103. For example, the monofocal zone is selected to correspond to the projection of the pupil diameter that is finally detected according to a set of predefined light environments and is associated with the statistical probability of the occurrence of the light environment. The monofocal zone 201b may additionally be surrounded by a customized connection zone 202b. The customized connection zone 202b connects the treated area of the anterior corneal surface - i.e., the monofocal zone 201b in this example - to the untreated area. The perimeter of the customized connection zone 202b can be arbitrarily selected such that the perimeter includes an irregular shape. The customized connection zone 202b can be used and its perimeter can be selected such that the risks of regression, corneal epithelial haze, and starburst effects are minimized, and it can further promote the healing of the cornea after treatment. Figure 1 As explained by the pupillometer 103, for example, the monofocal zone is selected to correspond to the projection of the pupil diameter that is finally detected according to a set of predefined light environments and is associated with the statistical probability of the occurrence of the light environment. The monofocal zone 201b may additionally be surrounded by a customized connection zone 202b. The customized connection zone 202b connects the treated area of the anterior corneal surface - i.e., the monofocal zone 201b in this example - to the untreated area. The perimeter of the customized connection zone 202b can be arbitrarily selected such that the perimeter includes an irregular shape. The customized connection zone 202b can be used and its perimeter can be selected such that the risks of regression, corneal epithelial haze, and starburst effects are minimized, and it can further promote the healing of the cornea after treatment.

[0092] Figure 2c Another schematic illustration showing a top view of a corneal region 200c. The corneal region includes a multifocal zone 201c and a customized connection zone 205c surrounding the multifocal zone 201c. Similar to that regarding Figure 2bAs explained, the customized connection region 205c can connect the periphery of the treated region of the anterior corneal surface - i.e., the multifocal region 201c in this example - to the untreated region. The multifocal region 201c can be further subdivided into a near vision region 202c, an intermediate vision region 203c, and a far vision region 204c. As explained in the example of reference Figure 2b , the multifocal region 201c and the sub-regions of the multifocal region 201c can be determined by the treating physician and / or Figure 1 the pupillometer 103. In addition, the operator can determine different refractive corrections and / or different refractive error maps for the sub-regions of the multifocal region 201c such that different aberration information and / or different desired focal points can be used in each region. The aberration information can include aberration information specific to one or more of the near vision region 202c, the intermediate vision region 203c, and the far vision region 204c. Similarly, the focal points of these regions can be different. Subsequently, the corresponding correction information for each region can be determined based on this information, as generally outlined herein, for example, by considering only the regions of the anterior corneal surface and the corresponding posterior corneal surface and the anterior lens surface and the corresponding posterior lens surface that belong to the respective regions. Thus, the near vision region 202c for vision in the near field of view, the intermediate vision region 203c for vision in the intermediate field of view, and the far vision region 204c for vision in the far field of view can be individually optimized. In other words, the correction information can include correction information specific to one or more of the near vision region 202c, the intermediate vision region 203c, and the far vision region 204c.

[0093] Figure 3 Another schematic illustration showing a corneal cross-section 300 is presented. The cross-section 300 shows the topographical information of the anterior corneal surface, i.e., the contour 301, and the topographical information of the posterior corneal surface, i.e., the contour 302. It further shows the topographical information of the anterior lens surface of the eye, i.e., the contour, and the topographical information of the posterior lens surface of the eye, i.e., the contour. The contours of both the anterior corneal surface and the posterior corneal surface can be obtained, for example, by the corneal tomographer 101 as explained in reference Figure 1 . The contours of both the anterior lens surface and the posterior lens surface of the eye can be obtained, for example, by an optical coherence tomographer (OCT) and / or the ultrasound scanning system 107, or they can be obtained from the database 109 as explained in reference Figure 1 . In addition, Figure 3Slopes 303 and 304 are depicted for each point on the anterior corneal surface 301 and the posterior corneal surface 302. There are also slopes 307 and 308 for each point on the anterior lens surface 305 and the posterior lens surface 306. Slopes 303, 304, 307, 308 are related to the refractive properties of the cornea and the refractive properties of the lens (for example, to calculate the refractive angle, as determined by Snell's law), and they can also be determined by the corneal tomography scanner 101 and the optical coherence tomography scanner and / or the ultrasound scanning system 107, respectively, or they can be obtained from the database 109 or derived from information provided by the corneal tomography scanner 101 and the optical coherence tomography scanner (OCT) and / or the ultrasound scanning system 107, respectively, for example, by calculating the corresponding tangents. As discussed in more detail below, the slope 303 of the anterior corneal surface can be modified by laser ablation so that a target profile of the anterior corneal surface 301 can be obtained that optimizes vision based on the refraction provided by the slope 304 of the posterior corneal surface 302 and the slopes 307 of the anterior lens surface 305 and 308 of the posterior lens surface 306.

[0094] Figure 4a Another schematic illustration of a corneal cross section 400a is shown. The cross section 400a includes topographic information of the anterior surface of the cornea, i.e., profile 401, and topographic information of the posterior surface of the cornea, i.e., profile 402. In addition, the schematic includes an iris plane 404, wherein the iris defines a pupil 403. The pupil 403 may correspond to a photopic pupil. The optical axis 420 may be defined, for example, based on the visual axis of the eye, such as the axis of symmetry of the cornea, such as selected by an operator. In addition, the center 405 of the anterior surface of the cornea may be defined, for example, as the corneal vertex or a light gaze reflection on the anterior surface of the cornea, or defined based on the corneal axis of symmetry, or selected by an operator.

[0095] Optionally, an area 401a of the anterior corneal surface may be determined, which corresponds to the projection of the photopic pupil (i.e., assuming that the light rays strike the cornea in a manner parallel to the optical axis). Thus, the area 401a of the anterior corneal surface relevant for determining the desired focal point may be determined (light rays striking other areas of the cornea will be blocked by the iris). Based on topographic information of the anterior corneal surface and the posterior corneal surface and based on the generally known refractive index of the cornea and the aqueous humor within the cornea, the light rays may be tracked by calculating the corresponding refractive angles, for example, based on Snell's law.

[0096] Figure 4b The topographic information based on the anterior corneal surface 401, the topographic information based on the posterior corneal surface 402, the topographic information based on the lens (e.g., from the Figure 1 The lens model of the estimated eye lens obtained from the interpreted database 109) is based on the topographic information of the front surface 431 of the lens, the topographic information of the rear surface 432 of the lens (for example, from the information aboutFigure 1 An example in which the database 109 as explained obtains a lens model of the estimated eye lens and determines a desired focal point based on refractive aberration information. In this example, the light ray 410 propagates toward the cornea in a direction parallel to the optical axis 420. The light ray is refracted by an optical member 450, such as a simulated lens, corresponding to the correction of the refractive aberration information. For example, if the refractive aberration information corresponds to subjective refraction with spherical aberration and cylindrical aberration having a relative axis, the optical member 450 can be a lens adapted to correct the spherical and cylindrical aberrations. In the case of more complex refractive aberration information, such as those involving higher-order aberrations, the optical member 450 can be defined accordingly, such as a simulated more complex lens.

[0097] The light ray 410 refracted by the optical member 450 then irradiates the anterior surface 401 of the cornea, propagates through the cornea, and irradiates the posterior surface 402 of the cornea, where the posterior surface of the cornea is separated from the anterior surface by a certain distance, as indicated by the distance 461 on the optical axis 420, and the distance can correspond to the corneal apex (where the distance information can be obtained from the biometer 108 and / or the tomograph 101 as explained). Then, the light ray propagates through the anterior chamber and irradiates the anterior surface 431 of the lens (such as the lens model obtained from the database 109 as explained). Subsequently, the light ray further propagates through the lens and irradiates the posterior surface 432 of the lens (such as the lens model obtained from the database 109 as explained), and the posterior surface of the lens can be located at a position separated from the anterior surface 401 of the cornea by a distance 462 and a distance 463 measured on the optical axis 420 (such as obtained from the biometer 108 as explained). Based on the topographical information of the anterior surface 401 and the posterior surface 402 of the cornea and the anterior surface 431 and the posterior surface 432 of the lens (such as the lens model obtained from the database 109 as explained), the refraction at these different surfaces can be calculated, and the light rays can be traced so that the intersection points with the optical axis 420 within the eye can be determined. Here, the calculation can be limited to the light rays irradiating on the area of the anterior surface 401 of the cornea, such as the area 401a determined as outlined. Alternatively, the calculation can be limited to any one of the areas 202c, 203c, or 204c outlined, such as in the case where near vision, intermediate vision, or far vision is to be analyzed separately. Figure 1 as explained and obtained by the biometer 108 and / or the tomograph 101). Then, the light ray propagates through the anterior chamber and irradiates the anterior surface 431 of the lens (such as the lens model obtained from the database 109 as explained). Figure 1 as explained and obtained by the biometer 108 and / or the tomograph 101). Then, the light ray propagates through the anterior chamber and irradiates the anterior surface 431 of the lens (such as the lens model obtained from the database 109 as explained). Figure 1 as explained and obtained by the biometer 108 and / or the tomograph 101). Then, the light ray propagates through the anterior chamber and irradiates the anterior surface 431 of the lens (such as the lens model obtained from the database 109 as explained). Figure 1 as explained and obtained by the biometer 108 and / or the tomograph 101). Then, the light ray propagates through the anterior chamber and irradiates the anterior surface 431 of the lens (such as the lens model obtained from the database 109 as explained). Figure 1 as explained and obtained by the biometer 108 and / or the tomograph 101). Then, the light ray propagates through the anterior chamber and irradiates the anterior surface 431 of the lens (such as the lens model obtained from the database 109 as explained). Figure 4a as outlined). Alternatively, the calculation can be limited to any one of the areas 202c, 203c, or 204c outlined, such as in the case where near vision, intermediate vision, or far vision is to be analyzed separately. Figure 2c as outlined). Alternatively, the calculation can be limited to any one of the areas 202c, 203c, or 204c outlined, such as in the case where near vision, intermediate vision, or far vision is to be analyzed separately.

[0098] Based on the intersection points, the desired focal point 440 can be determined. For example, the weighted average of all intersection points can be used. In the simplest case, centroid calculation can be used, or a calculation with different weighting factors can be used, such as giving more weight to the central ray. Depending on the radial distance between the center of vision and the corresponding illumination ray on the anterior corneal surface, a reduced weight can be given to the determined intersection points.

[0099] It should be noted that in other instances, the focal point can be defined in different ways, such as based on the refractive aberration that the operator wants to correct, based on the position of the fovea or retina of the patient's eye, or arbitrarily defined by the operator. The corresponding determination can be performed by the operator or a separate device. In this case, the device according to the invention has a corresponding interface for obtaining the desired focal point 440. However, the corresponding determination can also be performed by the device itself.

[0100] Based on the determined desired focal point 440, the distance 480 from the retina can be determined, which can be at a distance 464 relative to the anterior corneal surface (at the optical axis 420) (e.g., obtained by the biometer 108 as explained regarding Figure 1 This distance 480 defines the position of the desired focal point 440 relative to the retina and can be used as a reliability measure for, for example, the lens model obtained from the database 109 and / or the refractive aberration information provided by the operator 102 and / or obtained by the scanning refractometer and / or wavefront analyzer 104. For example, if the distance 480 is above a threshold, such as above 500 µm, more preferably above 300 µm, and most preferably above 100 µm, a warning, such as an audio signal, can be issued, which indicates to the operator, such as the treating physician, that the available data may be incorrect. The operator can then re-evaluate the obtained information.

[0101] Additionally or alternatively, the determination of the desired focal point 440 can also be based on reverse ray tracing. The determination based on forward ray tracing and reverse ray tracing can be applied as alternatives or supplements to each other, such as being alternately applied in one or more iterations or applied separately from each other, where the weighted average (or simple average) of the separately determined desired focal points can then be determined.

[0102] Figure 4cAnother step that can be implemented is shown, in which an area 401b of the anterior surface of the cornea is determined to which subsequent calculation of correction information and / or treatment can be limited. Area 401b can be determined based on a desired focal point 440 and a selected pupil diameter 403a, the selected pupil diameter being, for example, a pupil diameter ultimately associated with a statistical probability of occurrence of a light environment detected based on a set of predefined light environments or a pupil diameter to which the patient's actual pupil diameter in daily life is expected to be somewhat likely to be limited. For example, the diameter can be selected so that 80%-100%, preferably about 95%, of all situations in the patient's daily life include a pupil diameter that does not exceed the selected diameter.

[0103] Figure 1 The device shown, in particular the control unit 105, may be adapted to perform a reference Figures 4a-4c Any of the steps outlined.

[0104] Figure 5a A first example for determining correction information by reverse ray tracing is shown. In this example, the determination is based on light rays 410 emerging from a desired focal point 440, which is at a distance 480 relative to the retina. For each point or portion on a selected area 401b of the anterior corneal surface 401 (e.g., a point or portion in a grid, as outlined earlier) and the posterior corneal surface 402, the lens (e.g., from about Figure 1 The lens model obtained from the database 109 interpreted by Figure 1 For each corresponding point on the rear surface 432 of the lens model obtained from the database 109 interpreted by the user, the light can be traced. Figure 4b In the manner described, the posterior surface of the lens, the anterior surface of the lens, and the posterior surface of the cornea can be located at distances 461, 462, and 463, respectively, relative to the anterior surface of the cornea, and are exemplarily indicated with respect to the optical axis 420 (where these distances can be represented by the distances with respect to Figure 1 For each point, the correction information may be determined in the form of an angle 416 between a ray 410 exiting the cornea and a direction 415 of an optical axis 420. The angular deviation between the ray 410 exiting the cornea and the direction of the optical axis 420 indicates a refractive error. The determination may include determining the angle 416 between the ray 410 exiting the cornea and the direction of the optical axis 420. Figure 1 The lens model obtained from the database 109 interpreted by the invention is used to determine the refraction of the light 410 when it strikes the rear surface 432 of the lens (after propagating through the lens, which is, for example, from the lens about the Figure 1the refraction of the lens model obtained by the database 109 as explained, and determining the refraction of the light ray 410 when it impinges on the posterior corneal surface 402 (which may be included in or determined based on the topographical information of the posterior surface 402, such as the contour of the posterior surface). Similarly, it includes determining the refraction of the light ray 410 that impinges on the anterior corneal surface 401 having a local slope 490 (after propagating through the cornea).

[0105] Next, the local target slope 495 of the anterior surface 401 can be determined such that the light ray 410 impinging on the anterior surface having such a slope 495 will be refracted so that it exits the cornea along the direction 415 of the optical axis 420. Additionally or alternatively, the angle 496 between the local slope 490 and the local target slope 495 of the anterior surface 401 can be calculated. In this way, the local target slope 495 can be determined for each part or each point within the region 401b. For example, by integrating the local target slope 495, the desired target profile 470 of the region 401b of the anterior surface 401 (see Figure 5c ) can be determined in the form of correction information.

[0106] Optionally, then, the desired target profile 470 of the anterior corneal surface 401 within the region 401b is translated along the optical axis 420 such that a smooth transition between the target profile within the region 401b and the anterior surface 401 outside the region 401b can be obtained if needed. In this step, it is also ensured that all points of the target profile are within the actual profile of the anterior corneal surface 401.

[0107] Reference Figure 5a The above steps outlined can then be re-iterated one or more times, where the topographical information of the anterior surface is replaced with the target profile of the anterior surface obtained from the corresponding previous iteration. Such iterations can produce an increasingly improved target profile, which optimizes the focusing to the desired focal point 440. It is possible to apply a modification to the angle 496 in each iteration to optimize the focusing onto the desired focal point 440. By iterating this process, the focusing optimization onto the desired focal point 440 can be achieved.

[0108] In addition to or instead of translating the desired target profile 470 of the anterior corneal surface 401 within the region 401b (see Figure 5c ) along the optical axis 420 between iterations, such translation can also be performed as a final step, i.e., after the iterations are completed.

[0109] Based on the topographical information of the anterior surface 401 and the intersection points between the anterior surface of the cornea, defined as the determined target profile 470, which may include the connection zone 202b, the ablation volume can be determined. Thus, the correction information can also be provided in the form of the ablation volume.

[0110] In particular, in the calculations outlined with respect to Figure 5a it is beneficial to consider the topographical information of the posterior surface of the cornea as well as the lens model. Local irregularities in the posterior shape of the cornea can seriously affect the refraction at each point and the correction required at each point. Taking these factors into account improves the vision correction optimized for each patient and can minimize the ablation volume.

[0111] Figure 5b Another example for determining the correction information is shown, which is similar to the example shown in Figure 5a . However, instead of using the light rays emerging from the desired focal point 440 as outlined in reference Figure 5a , light rays 410 that are incident on the selected area 401b of the cornea in a manner parallel to the optical axis 420 are used, i.e., forward ray tracing is used. Similarly, as outlined in reference Figure 5a , based on the local slopes 490 of the anterior surface 401 of the cornea, the posterior surface 402 of the cornea, the anterior surface 431 of the lens model, and the posterior surface 432 of the lens model, each ray 410 can be traced until it intersects the optical axis 420 within the eye. For each ray, the position deviation 417 of the intersection point relative to the desired focal point 440 can be determined.

[0112] The local target slope 495 of the anterior surface 401 can be determined such that the light ray 410 is focused onto the desired focal point 440 (or the deviation from the desired focal point is minimized). Additionally or alternatively, the angle 496 between the local slope 490 and the local target slope 495 of the anterior surface can be determined. In this way, the local target slope 495 can be determined for each part or each point within the selected area 401b. For example, by integrating the local target slope 495, the desired target profile of the anterior surface 401 can be determined, as outlined above in reference Figure 5a . Furthermore, for the example outlined in reference Figure 5b , the iteration and / or the translation along the optical axis 420 can also be performed in a similar manner.

[0113] Similarly, as explained in reference Figure 5a , considering the topographical information of the posterior surface 402 of the cornea, the anterior surface 431 and the posterior surface 432 of the lens model, as well as the respective distance information 461, distance information 462, distance information 463, distance information 464 is also particularly beneficial for the determination of Figure 5b .

[0114] refer to Figure 5a and 5b The outlined determinations may be applied as an alternative or in addition to each other, for example alternately in one or more iterations or separately from each other, wherein a weighted average (or simple average) of the respectively determined correction information may then be determined. Region 401b may be selected as any of the regions outlined herein.

[0115] Figure 1 The device shown, in particular the control unit 105, may be adapted to perform a reference Figures 5a-5b Any of the steps outlined.

[0116] Figure 5c Another exemplary cross section is shown, in which the image reference Figures 5a-5b Exemplary corrective information in the form of a target profile 470 of the anterior corneal surface determined as outlined.

[0117] Figure 6a Another example for determining correction information by reverse ray tracing is shown. In this example, the determination is based on light rays 410 emerging from the retinal surface 445. For each point or portion on the selected area 401b of the anterior corneal surface 401 (e.g., a point or portion in a grid, as outlined earlier) and the posterior corneal surface 402, the lens (e.g., as described by the reference numeral 404), the retinal surface 445, and the retinal surface 446, the retinal surface 447, the retinal surface 448, the retinal surface 449, the retinal surface 450, the retinal surface 451, the retinal surface 452, the retinal surface 454, the retinal surface 455, the retinal surface 456, the retinal surface 457, the retinal surface 458, the ret Figure 1 The anterior surface 431 and the lens (e.g., obtained by the OCT and / or ultrasound scanning system 107 explained) are Figure 1 For each corresponding point on the rear surface 432 obtained by the OCT and / or ultrasound scanning system 107 as explained above, the light can be tracked. Figure 4b In the manner described, the posterior surface of the lens, the anterior surface of the lens, and the posterior surface of the cornea can be located at distances 461, 462, and 463, respectively, relative to the anterior surface of the cornea, and are exemplarily indicated with respect to the optical axis 420 (where these distances can be represented by the distances with respect to Figure 1 For each point, the correction information may be determined in the form of an angle 416 between a ray 410 leaving the cornea and a direction 415 of an optical axis 420. The angular deviation between the ray 410 leaving the cornea and the direction of the optical axis 420 indicates a refractive error. The determination may include determining the angle 416 between the ray 410 leaving the cornea and the direction 415 of the optical axis 420. Figure 1 The refraction of the light 410 when it strikes the posterior surface 432 of the lens (obtained by the OCT and / or ultrasound scanning system 107 explained above) determines the refraction of the light 410 when it strikes the anterior surface 431 of the lens (after propagating through the lens, which is, for example, formed by the lens of FIG. Figure 1The refraction obtained by the OCT and / or ultrasound scanning system 107 as explained, and the refraction of the light ray 410 when it impinges on the posterior corneal surface 402 (which may be included in or determined based on the topographic information of the posterior surface 402, such as the contour of the posterior surface). Similarly, it includes determining the refraction of the light ray 410 that impinges on the anterior corneal surface 401 having a local slope 490 (after propagating through the cornea).

[0118] Subsequently, the local target slope 495 of the anterior surface 401 can be determined such that the light ray 410 impinging on the anterior surface having such a slope 495 will be refracted so that it exits the cornea in the direction 415 along the optical axis 420. Additionally or alternatively, the angle 496 between the local slope 490 and the local target slope 495 of the anterior surface 401 can be calculated. In this way, the local target slope 495 can be determined for each part or each point within the region 401b. For example, by integrating the local target slope 495, the desired target profile 470 of the region 401b of the anterior surface 401 (see Figure 6c below) can be determined in the form of correction information.

[0119] Optionally, then, the desired target profile 470 of the anterior corneal surface 401 within the region 401b is translated along the optical axis 420 so that a smooth transition between the target profile within the region 401b and the anterior surface 401 outside the region 401b can be obtained if needed. In this step, it is also ensured that all points of the target profile are within the actual profile of the anterior corneal surface 401.

[0120] Reference Figure 6a The above steps outlined can then be re-iterated one or more times, where the topographic information of the anterior surface is replaced by the target profile of the anterior surface obtained from the corresponding previous iteration. Such iterations can result in an increasingly improved target profile, which optimizes the focusing onto the retinal surface 445. It is possible to apply a modification to the angle 496 in each iteration to optimize the focusing onto the retinal surface 445. By iterating this process, the focusing optimization onto the retinal surface 445 can be achieved.

[0121] In addition to or instead of translating the desired target profile 470 of the anterior corneal surface 401 within the region 401b (see Figure 6c below) along the optical axis 420 between iterations, such translation can also be performed as a final step, i.e., after the iterations are completed.

[0122] The ablation volume can be determined based on the topographical information of the anterior surface 401 and the intersection points between the anterior surface of the cornea, defined as the target contour 470 of the anterior surface of the cornea 202a - which may include a junction zone 202b. Thus, the correction information can also be provided in the form of an ablation volume.

[0123] In particular, in the calculations outlined with respect to Figure 6a it is beneficial to consider the topographical information regarding the posterior surface of the cornea as well as the anterior and posterior surfaces of the lens. Local irregularities in the posterior shape of the cornea can significantly affect the refraction at each point and the correction required at each point. Taking these factors into account improves the vision correction optimized for each patient and can minimize the ablation volume.

[0124] Figure 6b Another example for determining the correction information is shown, which is similar to the example shown in Figure 6a . However, instead of using the light rays emerging from the retinal surface 445 as outlined in reference Figure 6a , light rays 410 that are incident on a selected area 401b of the cornea in a manner parallel to the optical axis 420 are used, i.e., forward ray tracing is used. Similarly, as outlined in reference Figure 6a , based on the local slopes 490 of the anterior surface 401 of the cornea, the posterior surface 402 of the cornea, the anterior surface 431 of the lens, and the posterior surface 432 of the lens, each light ray 410 can be traced until it intersects the optical axis 420 within the eye. For each light ray, the position deviation 417 of the intersection point relative to the retinal surface 445 can be determined.

[0125] The local target slope 495 of the anterior surface 401 can be determined such that the light ray 410 is focused onto the retinal surface 445 (or the deviation from the retinal surface is minimized). Additionally or alternatively, the angle 496 between the local slope 490 and the local target slope 495 of the anterior surface can be determined. In this way, the local target slope 495 can be determined for each part or each point within the selected area 401b. For example, by integrating the local target slope 495, the desired target contour of the anterior surface 401 can be determined, as outlined above in reference Figure 6a . Furthermore, iterations and / or translations along the optical axis 420 can also be performed in a manner similar to that described in reference Figure 6a .

[0126] Similarly, as explained in reference Figure 6a it is also particularly beneficial to consider the topographical information regarding the posterior surface 402 of the cornea, the anterior surface 431 of the lens, and the posterior surface 432 of the lens, as well as the respective distance information 461, distance information 462, distance information 463, distance information 464 for the determination of Figure 6b .

[0127] Reference Figure 6a and 6b The determinations outlined can be applied as alternatives or supplements to each other, for example, applied alternately in one or more iterations or applied separately from each other, where the weighted average (or simple average) of the separately determined correction information can then be determined. Region 401b can be selected as any of the regions outlined herein.

[0128] Figure 1 The device shown, particularly the control unit 105, can be adapted to perform any of the steps outlined in Figures 6a-6b reference.

[0129] Figure 6c Another exemplary cross-section is shown, in which exemplary correction information in the form of a target profile 470 of the anterior corneal surface determined as outlined in Figures 6a-6b reference is shown.

[0130] Additionally or alternatively, topographic information regarding the anterior corneal surface 401 and the posterior corneal surface 402, topographic information regarding the anterior lens surface 433 and the posterior lens surface 434, and possibly also the respective distance information 461, distance information 462, distance information 463, distance information 464 obtained as described with respect to Figure 6a reference can be used to determine the desired focal point 440 in a manner similar to that described with respect to Figures 4a to 4c reference. In a manner similar to that described above, the distance 480 of the determined desired focal point relative to the retina can be determined. If this distance is higher than a second threshold, for example, higher than 500 µm, more preferably higher than 300 µm, and most preferably higher than 100 µm, a warning can be issued in a manner similar to that described above.

Claims

1. An apparatus (100) for correcting visual refractive errors, which comprises: a. a component (101) for obtaining topographical information of a measurement of the anterior corneal surface (401) of an individual's eye and topographical information of a measurement of the posterior corneal surface (402); b. a component (107) for obtaining topographical information of a measurement of the anterior lens surface (431) of the individual's eye and topographical information of a measurement of the posterior lens surface (432); c. a component for obtaining distance information (464) of a measurement of the retina of the eye relative to the anterior corneal surface (401) of the individual's eye; d. a component (105) for determining correction information (416, 496) related to the anterior corneal surface (401) based on the topographical information of the measurements of the anterior corneal surface (401) and the posterior corneal surface (402) and the topographical information of the measurements of the anterior lens surface (431) and the posterior lens surface (432) to optimize focusing onto the retina of the eye.

2. The apparatus (100) according to claim 1, wherein the topographical information of the measurement of the anterior lens surface (431) of the eye and the topographical information of the posterior lens surface (432) are obtained for near vision and / or distance vision.

3. The apparatus (100) according to claim 1 or 2, wherein the component (105) for determining the correction information (416, 496) is adapted to perform ray tracing on at least one ray (410) that passes through the cornea and is refracted by the anterior corneal surface (401) and the posterior corneal surface (402) and passes through the lens and is refracted by the anterior lens surface (431) and the posterior lens surface (432) based on the topographical information of the measurements of the anterior corneal surface (401) and the posterior corneal surface (402) and the topographical information of the measurements of the anterior lens surface (431) and the posterior lens surface (432) to optimize focusing on the retina.

4. The apparatus (100) according to any one of claims 1 to 3, further comprising a component (108) for obtaining at least one of distance information (461) of the posterior corneal surface of the individual's eye relative to the anterior corneal surface, distance information (462) of the anterior lens surface relative to the anterior corneal surface, and distance information (463) of the posterior lens surface relative to the anterior corneal surface; and wherein the component (105) for determining correction information (416, 496) related to the anterior corneal surface (401) to optimize focusing onto the retina of the eye is further adapted to perform the determination based on the at least one obtained distance information (461, 462, 463).

5. A computer program for correcting visual refractive errors, comprising instructions that, when executed, cause the apparatus (100) according to any one of claims 1 to 4 to perform the following operations: a. Obtain the measured topographic information of the anterior corneal surface (401) and the measured topographic information of the posterior corneal surface (402) of an individual's eye; b. Obtain the measured topographic information of the anterior lens surface (431) and the measured topographic information of the posterior lens surface (432) of the individual's eye; c. Obtain the distance information (464) of the retina of the eye relative to the anterior corneal surface (401) of the individual's eye; d. Based on the measured topographic information of the anterior corneal surface (401) and the posterior corneal surface (402) and the measured topographic information of the anterior lens surface (431) and the posterior lens surface (432), determine correction information (416, 496) related to the anterior corneal surface (401) to optimize the focusing onto the retina of the eye.

6. A method for determining vision refractive error correction information, which comprises the following steps: a. Obtain the measured topographic information of the anterior corneal surface (401) and the measured topographic information of the posterior corneal surface (402) of an individual's eye; b. Obtain the measured topographic information of the anterior lens surface (431) and the measured topographic information of the posterior lens surface (432) of the individual's eye; c. Obtain the distance information (464) of the retina of the eye relative to the anterior corneal surface (401) of the individual's eye; d. Based on the measured topographic information of the anterior corneal surface (401) and the posterior corneal surface (402) and the measured topographic information of the anterior lens surface (431) and the posterior lens surface (432), determine correction information (416, 496) related to the anterior corneal surface (401) to optimize the focusing onto the retina of the eye.

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