Postoperative vignetting prediction in pseudophakic eyes

Abstract

A system for predicting post-operative vignetting in an eye of a subject includes a controller having a processor and a tangible non-transitory memory having instructions recorded thereon. The controller is in communication with a diagnostic module adapted to store pre-operative anatomic data of the eye as an eye model. The system includes a projection module and a ray tracing module selectively executable by the controller. The projection module is adapted to determine estimated post-operative variables of the eye based at least in part on the pre-operative anatomic data and the intraocular lens. The ray tracing module is adapted to calculate light propagation through the eye. The ray tracing module is executed to determine light distribution at respective visual field angles across a predetermined visual field. The controller is configured to determine one or more post-operative vignetting parameters based at least in part on the light distribution.

Description

BACKGROUND

[0001] The present disclosure relates generally to predicting post-operative vignetting in a subject's eye prior to the eye being implanted with an intraocular lens. More specifically, the present disclosure relates to a system and method for obtaining one or more post-operative vignetting parameters of a pseudophakic eye (an eye with an implanted lens). The human lens is normally clear, so light can pass through it easily. However, many factors can cause regions in the lens to become cloudy and dense, negatively impacting the quality of vision. This condition can be corrected via cataract surgery, i.e., selecting an artificial lens to implant in the patient's eye. In fact, cataract surgery is very commonly performed worldwide. After cataract surgery, many patients experience negative dysphotopsia, a condition characterized by a dark shadow in the patient's peripheral vision. This shadow is believed to be caused by light vignetting in the pseudophakic eye. In some cases, the phenomenon persists for a long time after surgery. Some cases can require secondary surgical intervention. Currently, there is no objective means to determine, prior to cataract surgery, a patient's individual risk of developing a certain type of negative dysphotopsia and its potential severity. SUMMARY

[0002] Disclosed herein is a system for predicting post-operative vignetting in a subject's eye prior to implanting an intraocular lens. The system includes a controller having a processor and a tangible non-transitory memory having instructions recorded thereon. The controller is in communication with a diagnostic module adapted to store pre-operative anatomic data of the eye as an eye model. The system includes a projection module and a ray tracing module selectively executable by the controller. The projection module is adapted to determine estimated post-operative variables of the eye based at least in part on the pre-operative anatomic data and the intraocular lens. The ray tracing module is adapted to compute light propagation through the eye. The controller is configured to obtain the pre-operative anatomic data of the eye via the diagnostic module. The controller is configured to determine the estimated post-operative variables of the eye via the projection module and incorporate the estimated post-operative variables into the eye model. The ray tracing module is executed to determine light distribution at respective visual field angles across a predetermined visual field in the eye model. The controller is configured to determine one or more post-operative vignetting parameters based at least in part on the light distribution at the respective visual field angles.

[0003] The ray tracing module traces bundles of rays propagating through the eye. The post-operative vignetting parameters can include a first angle of view defined as a smallest angle of view of a respective angle of view of the optical zone of the intraocular lens through which at least a portion of the bundle of rays passing through the pupil of the eye will not pass. The post-operative vignetting parameters can include a second angle of view defined as a smallest angle of view of the respective angle of view of the optical zone of the intraocular lens through which the bundle of rays passing through the pupil will not pass. The post-operative vignetting parameters can include a third angle of view defined as a smallest angle of view of the respective angle of view of the intraocular lens through which the bundle of rays passing through the pupil will completely miss.

[0004] In some embodiments, the pre-operative anatomic data includes an axial length of the eye. The pre-operative anatomic data can include respective locations and respective contours of an anterior corneal surface and a posterior corneal surface of the eye. The pre-operative anatomic data can include a location, an orientation, and a size of a pupil of the eye in a three-dimensional coordinate system, the pupil being in photopic conditions. The estimated post-operative variables of the eye can include a respective location and a respective orientation of the intraocular lens. The estimated post-operative variables of the eye can include a respective location and a respective orientation of the pupil and / or the iris of the eye.

[0005] In some embodiments, the ray tracing module is adapted to trace bundles of rays propagating through the intraocular lens backward until reaching the retina of the eye. The bundles of rays are focused into infinitesimal spots on the retina. The ray tracing module can be adapted to employ respective indices of refraction in the eye suitable for light having a wavelength of 550 nanometers.

[0006] Disclosed herein is a method for predicting post-operative vignetting in an eye of a subject prior to implanting an intraocular lens by a system having a controller having a processor and a tangible non-transitory memory on which instructions are recorded. The method includes adapting, via at least one imaging device, a diagnostic module to store pre-operative anatomic data of the eye as an eye model. Adapting, via the controller, a projection module to determine estimated post-operative variables of the eye based at least in part on the pre-operative anatomic data and the intraocular lens.

[0007] The method includes adapting a ray tracing module to calculate light propagation through the eye, the ray tracing module being selectively executable by the controller. Obtaining, via the diagnostic module, pre-operative anatomic data of the eye. The method includes determining, via the projection module, estimated post-operative variables of the eye and incorporating the estimated post-operative variables into the eye model. Executing the ray tracing module to determine light distribution at respective angles of view across a predetermined field of view in the eye model. The method includes determining one or more post-operative vignetting parameters based at least in part on the light distribution at the respective angles of view.

[0008] The above features and advantages and other features and advantages of the present disclosure will be readily apparent from the following detailed description of the presently preferred embodiment, taken in connection with the drawing, wherein: BRIEF DESCRIPTION OF DRAWINGS

[0009] Figure 1 is a schematic illustration of a system for predicting post-operative vignetting in an eye having a controller;

[0010] Figure 2 is a schematic flowchart of a method that can be performed by the controller of Figure 1

[0011] Figure 3 is a schematic partial view of an example model of a pseudophakic eye illustrating post-operative vignetting;

[0012] Figure 4 is a schematic partial cross-sectional view of an example pre-operative image of an eye; and

[0013] Figure 5 is a schematic partial cross-sectional view of an example post-operative image of an eye. DETAILED DESCRIPTION

[0014] Referring to the drawings, wherein like reference numerals refer to like components, Figure 1 A system 10 for predicting parameters related to post-operative vignetting in an eye E for a subject 12 who is a candidate for cataract surgery is schematically illustrated. It should be understood that the drawings are intended to be illustrative and not drawn to scale. Reference is made to Figure 1 The system 10 includes a controller C having at least one processor P and at least one memory M (or non-transitory, tangible computer readable storage medium) on which instructions for performing a method 100 are recorded, which is described in detail below with reference to Figure 2 The memory M can store a set of controller-executable instructions and the processor P can execute the set of controller-executable instructions stored in the memory M.

[0015] Post-operative vignetting is a localized obscuration in the field of view or image plane that occurs in a subject 12 after cataract surgery. Vignetting can be described as a dimming or loss of image brightness perceived by the subject 12 and is typically seen at the edges of the image. The occurrence of vignetting is due to the partial or complete obstruction of light before it reaches the image plane by an aperture. In some cases, a portion of the incoming light is obstructed while another portion of the light still passes through the optical system. Here, the remaining light continues to form an image, but not as bright as it would have been originally. Post-operative vignetting is associated with negative glare ghosting, a condition that can require secondary surgical intervention.

[0016] Figure 3 ​is a diagram illustrating post-operative vignetting in pseudophakic eye 200. Pseudophakic eye 200 has intraocular lens 202, which has optical zone 204, which is the effective focusing or refractory portion of intraocular lens 202. Figure 3 Also shown in FIG. 2A are corneal anterior surface 206A, corneal posterior surface 206B, pupil 208, iris 210, retina 212, and visual axis A. With reference to Figure 3 , light beam B enters pupil 208 at a relatively large field angle. Pupil 208 and iris 210 act as a system stop to define the extent of light that forms an image perceived by subject 12. When entire light beam B travels through pupil 208, some portions of this light beam do not travel through intraocular lens 202.

[0017] With reference to Figure 3 , first light beam portion 214 of light beam B misses optical zone 204 entirely and is delivered directly at first retinal location 216 of retina 212. Second light beam portion 218 passes through intraocular lens 202 and is focused at second retinal location 220. Intervening between first retinal location 216 and second retinal location 220 is intermediate retinal location 222 that is not illuminated at all by light beam B. While second retinal location 220 is illuminated, it is only partially illuminated because only a small portion of light beam B at this angle (i.e., a small portion that passes through optical zone 204) is focused by intraocular lens 202.

[0018] The combination of second retinal location 220 and intermediate retinal location 222 can be perceived by subject 12 as a dark shadow. This dark shadow can be accentuated by the brighter illumination in second retinal location 220. In Figure 3 In the embodiment shown, subject 12 will perceive first retinal location 216 to appear at a larger field angle than second retinal location 220, even though the light that gives rise to both retinal locations is from a single direction.

[0019] System 10 (via execution of method 100) provides an assessment of the potential severity of vignetting in pseudophakic eye 200 based on pre-operative information. The technical advantage of system 10 is that the clinician will have this information prior to cataract surgery and can appropriately advise subject 12 and, if appropriate, adjust the treatment plan (e.g., implant type, implant location, optical power).

[0020] As described below, with reference to Figure 1, the system 10 can include a diagnostic module 20 for storing pre-operative anatomic data of the eye E. The pre-operative anatomic data can be obtained from at least one imaging device 22. The system 10 can include a projection module 24 and a ray tracing module 26 that can be selectively executed by the controller C. The projection module 24 is adapted to predict post-operative anatomic parameters of the eye E based at least in part on the pre-operative anatomic data. The ray tracing module 26 is adapted to trace a bundle of rays 230 propagating through the pseudophakic eye 200, as described below.

[0021] Reference is made to Figure 1 , the system 10 can include a user interface 28 that can be operated by a user. The user interface 28 can include a touch screen or other input device. The controller C can be configured to process signals to and from the user interface 28 and a display (not shown). Additionally, the user interface 28 and / or the controller C can be in communication with a lens selection module 30.

[0022] The various components of the system 10 can be configured to communicate via a network 32, as Figure 1 indicated. The diagnostic module 20, the projection module 24, and the ray tracing module 26 can be embedded in the controller C. Alternatively, the diagnostic module 20, the projection module 24, and the ray tracing module 26 can be part of a remote server or cloud unit accessible to the controller C via the network 32. The network 32 can be a bidirectional bus implemented in a variety of different ways, such as a serial communication bus in the form of a local area network. The local area network can include, but is not limited to, a controller area network (CAN), a controller area network with flexible data rate (CAN-FD), an Ethernet, a WIFI, a Bluetooth TM , and other forms of data connection. Other types of connection can be employed.

[0023] Reference is now made to Figure 2 , a flowchart of a method 100 for predicting post-operative vignetting in a pseudophakic eye 200 is shown. The method 100 can be wholly or partially executable by the controller C. The method 100 need not be applied in the particular order described herein. Additionally, it should be appreciated that some blocks can be omitted. The method 100 begins at block 102. Figure 1

[0024] According to Figure 2 block 102, the controller C is configured to obtain pre-operative anatomic data of the eye E, which can be stored in the diagnostic module 20 as part of the eye model 21. The pre-operative anatomic data (including biometric data) can be obtained from at least one imaging device 22. The imaging device 22 can include a topography device, an ultrasound machine, an optical coherence tomography machine, a magnetic resonance imaging machine, or other imaging device available to those skilled in the art. The pre-operative anatomic data can be derived from a single image or multiple images.​

[0025] Figure 4 A schematic example of a pre-operative image 300 of an eye E comprising a natural lens 302 is shown. The pre-operative image 300 can be obtained via an ultrasound biomicroscopy technique. The ultrasound biomicroscopy technique can employ a relatively high frequency transducer of between about 35 MHz and 100 MHz, with a tissue penetration depth of between about 4 mm and 5 mm. With reference to Figure 4 , the pre-operative anatomical data comprises a respective position, a respective orientation and a size of the pupil 308 under photopic conditions. Photopic conditions refer to vision under conditions of bright light, which vision is mainly due to the cone cells in the eye. In some embodiments, photopic conditions can be defined to encompass an adaptation level of 3 candela per square meter (cd / m 2 ) or more.

[0026] With reference to Figure 4 , the pre-operative anatomical data comprises a respective position and a respective orientation of the iris 310 and the natural lens 302. The respective orientation comprises a tilt with respect to the XYZ coordinate system. The respective position of the pupil 308, the iris 310 and the natural lens 302 can be specified in three dimensions in the XYZ coordinate system; i.e. along the X-axis as well as along the Y-axis and the Z-axis. The XYZ coordinate system can be defined such that the X-axis is parallel to the visual axis A. Alternatively, the XYZ coordinate system can be defined such that the X-axis is parallel to another geometric axis or optical axis (not shown). Here, the eye model 21 will comprise a position and an orientation of the visual axis A.

[0027] With reference to Figure 4 , the pre-operative anatomical data can comprise a lens thickness 320, an anterior chamber depth 322 and a cornea thickness 324. In addition, the eye model 21 in the diagnostic module 20 contains refractive indices of different parts of the eye E. The pre-operative anatomical data comprises an axial length 240 of the eye E (as shown in Figure 3 ).

[0028] The diagnostic module 20 can be selectively executed to estimate surfaces in the eye E either approximately or in a parametric representation based on the pre-operative anatomical data and algorithms available to the skilled person. Figure 1 The eye model 21 can comprise shapes and positions of the corneal anterior surface 306A and the corneal posterior surface 306B over the entire area where light of interest can enter the eye E (see Figure 4 ). The eye model 21 can further comprise shapes and positions of the lens anterior surface 314 and the lens posterior surface 312 (see Figure 4 ). Since the eyeball typically has a near-spherical shape, the eye model 21 can estimate a surface of the retina 212 (as shown in Figure 2 ) approximately from the axial length 240.

[0029] Method 100 proceeds from block 102 to block 104. According to block 104, controller C is configured to determine an estimated post-operative variable of eye E based in part on pre-operative anatomic data. The estimated post-operative variable can be obtained by projection module 24. In some embodiments, projection module 24 contains intraocular lens power calculation formulas available to those skilled in the art, such as the SRK / T formula, the Holladay formula, the Hoffer Q formula, the Olsen formula, and the Haigis formula. In other embodiments, projection module 24 contains a machine learning module, such as a neural network, trained to determine the estimated post-operative variable from a large number of historical pairings of pre-operative data and post-operative data. Historical pairings refer to pre-operative data and post-operative data of the same person (e.g., Figure 4 and Figure 5 ). It should be appreciated that the estimated post-operative variable can be obtained from other estimation methods available to those skilled in the art.

[0030] Figure 5 A schematic example of a post-operative image 400 of eye E is shown. Figure 5 Also shown are intraocular lens 402 with support structure or haptic 403, corneal anterior surface 406A, corneal posterior surface 406B, pupil 408, and iris 410. The estimated post-operative variable includes respective positions and respective orientations or tilts (relative to the XYZ coordinate system) of intraocular lens 402, pupil 408, and / or iris 410. Post-operatively, pupil 408 can be decentred or tilted relative to visual axis A. In pre-operative image 300, iris 310 can be forwardly convex and offset (relative to post-operative image 400) due to the relatively large shape of natural lens 302. In post-operative image 400, iris 410 can assume a relatively more planar geometry.

[0031] Method 100 proceeds from block 104 to block 106. According to block 106 of Figure 2 , controller C is configured to determine a light distribution of eye E across a predetermined visual field based on data obtained in block 102 and block 104. With reference to Figure 3 , the predetermined visual field can be defined as an arc along retina 212 between a starting retinal location 234 and an ending retinal location 236. The light distribution can be obtained via ray tracing module 26 (see Figure 1 ). With reference to Figure 3 ,( Figure 1 ) ray tracing module 26 is adapted to trace a bundle of rays 230 propagating through corneal anterior surface 206A and corneal posterior surface 206B of pseudophakic eye 200.

[0032] Figure 3The bundle of rays 230 is propagated backwards through the intraocular lens 202 until reaching the retina 212. The ray tracing module 26 employs the eye model 21 (from block 102) replacing the estimated post-operative variables (such as the respective positions and respective tilts of the pupil 208, iris 210 and intraocular lens 202) obtained in block 104. Optionally, the ray tracing module 26 can assume that effects related to the wave nature of light can be neglected, so that the propagation of light is described in terms of rays.

[0033] The propagation is tracked using reflections and refractions using Snell's law, which describes the refraction of a ray of light when entering a medium with a different optical density. In other words, when a respective ray of the bundle of rays 230 encounters a surface, the new direction of the respective ray is determined according to Snell's law using the refractive indices stored in the diagnostic module 20. In some embodiments, the ray tracing module 26 employs refractive indices applicable for light having a wavelength of 550 nm (green light). The bundle of rays 230 is focused into an infinitesimally small spot 232 at the retina 212, and the spatial distribution of the bundle of rays 230 on the retina 212 is recorded. The spatial distribution can be represented by a point spread function map along the retina 212.

[0034] The ray tracing module 26 provides an evaluation of the focusing properties of the pseudophakic eye 200 by covering respective viewing angles of a predetermined visual field by moving the bundle of rays 230 in incremental steps. As mentioned above, the predetermined visual field can be defined as an arc of a circle along the retina 212 between a starting retinal position 234 and an ending retinal position 236. The light distribution reflects the amount of light impinging on (and thus passing through) the retina 212 as a function of the angle of incidence of the bundle of rays 230. In occluded regions (such as at high viewing angles), the spatial distribution (represented by the point spread function map) of the bundle of rays 230 is flat and / or bifurcated.

[0035] The method 100 proceeds from block 106 to block 108. According to Figure 2 In block 108, the controller C is configured to determine one or more post-operative vignetting parameters of the pseudophakic eye 200 based on the light distribution obtained in block 106. The post-operative vignetting parameters include viewing angle for different regions in the retina 212. With reference to Figure 3 The post-operative vignetting parameters include a first viewing angle V1, a second viewing angle V2 and a third viewing angle V3.

[0036] With reference to Figure 3The first visual angle V1 is defined as the smallest of the respective field angles of the optical zone 204 of the intraocular lens 202 through which at least a portion of the bundle of light rays 230 passing through the pupil 208 will not pass. The size of the first visual angle V1 indicates where the vignetting can first begin. The second visual angle V2 is defined as the smallest of the respective field angles of the optical zone 204 of the intraocular lens 202 through which the bundle of light rays 230 passing through the pupil 208 will not pass.

[0037] The second visual angle V2 indicates where light that completely misses the intraocular lens will be perceived. The third visual angle V3 is defined as the smallest of the respective field angles of the optical zone 204 of the intraocular lens 202 through which the bundle of light rays 230 passing through the pupil 208 will completely miss. The third visual angle V3 indicates where the image perceived by the subject 12 can completely turn black. The visual angles are helpful in determining the impact of post-operative vignetting on the subject 12, including useful information about the likelihood and potential extent of negative glare halos after cataract surgery.

[0038] From block 108, the method 100 proceeds to block 110. According to block 110, the controller C is configured to determine whether the post-operative vignetting parameters obtained in block 108 are within respective predetermined thresholds (i.e., separate thresholds for each factor). The respective thresholds can be defined or selected based on off-the-shelf applications, and the respective thresholds can vary based on the subject 12. In one example, for the first visual angle V1, the second visual angle V2, and the third visual angle V3, the respective predetermined thresholds are 75 degrees, 80 degrees, and 85 degrees, respectively.

[0039] If the post-operative vignetting parameters are within the respective predetermined thresholds, the method 100 ends. If the post-operative vignetting parameters are not within the respective predetermined thresholds, the method 100 can proceed to block 112 to determine what modifications can be appropriate. For example, if the size of at least one of the first visual angle V1, the second visual angle V2, and the third visual angle V3 is below the respective predetermined threshold, the surgical plan can be changed to incorporate one or more alternative techniques to mitigate the occurrence and / or severity. Because trade-offs are involved, the alternative techniques can not typically be implemented.

[0040] Referring to Figure 5 The modification can include reducing the spacing 426 between the iris 410 and the intraocular lens 402. Reducing the distance between the body of the intraocular lens 402 and the iris 410 will result in improved vignetting. As the spacing 426 increases, less light is encountered by the intraocular lens 402 and the field angles increase.

[0041] Referring to Figure 5modifications can include using an intraocular lens 402 with a larger diameter 428. Increasing the diameter of the intraocular lens 402 places the lens surface in the current gap. In one example, expanding the diameter 428 of the intraocular lens 402 from 6 mm to 7 mm pushes the 70% flux field from 81 degrees to 83.5 degrees. This is approximately equivalent to moving a 6 mm lens forward by 100 microns in one eye model. The modifications can further include implanting the intraocular lens 402 into the ciliary sulcus instead of the capsular bag.

[0042] If each of the first, second, and third visual angles VI, V2, and V3 are below the respective threshold, the controller C can be configured to select a different intraocular lens (e.g., a different model and / or optical power) via the lens selection module 30 and repeat the steps of the method 100. Additionally, a clinician can provide consultation and manage expectations.

[0043] In summary, the system 10 inputs pre-operative anatomic data of an eye E that is to receive a cataract surgery, predicts a plurality of different post-operative anatomic parameters, and uses raytracing optical analysis to calculate a plurality of different parameters related to post-operative vignetting. The system 10 can be used in any procedure for which sufficient pre-operative anatomic data is available to allow accurate tracing by the raytracing module 26.

[0044] Figure 1 The controller C includes computer-readable media (also referred to as processor-readable media) including non-transitory (e.g., tangible) media that participate in providing data (e.g., instructions) that can be read by a computer (e.g., by a processor of a computer). Such media can take many forms, including but not limited to non-volatile media and volatile media. Non-volatile media can include, for example, optical or magnetic disks and other persistent memory. Volatile media can include, for example, dynamic random access memory (DRAM), which can constitute a main memory. Such instructions can be transmitted by one or more transmission media including coaxial cables; copper wire and fiber optic cables; including wires that comprise a system bus coupled to a processor of a computer. Some forms of computer-readable media include the following: a floppy disk; a flexible disk; a hard disk; magnetic tape; other magnetic media; a CD-ROM; DVDs; other optical media; punch cards; paper tape; other physical media with patterns of holes; a RAM; a PROM; an EPROM; a FLASH-EPROM; any other memory chip or cartridge; or any other medium from which a computer can read.

[0045] The lookup tables, databases, data repositories, or other data stores described herein can include various kinds of mechanisms for storing, accessing, and retrieving various kinds of data, including a hierarchical database, a set of files in a file system, an application database in a proprietary format, a relational database management system (RDBMS), etc. Each such data store can be included within a computing device employing a computer operating system such as one of those mentioned above, and can be accessed via a network in any one or more of a variety of manners. A file system can be accessed from the computer operating system and can include files stored in various formats. An RDBMS can employ the Structured Query Language (SQL) in addition to a language for creating, storing, editing, and executing stored procedures, such as the PL / SQL language mentioned above.

[0046] DETAILED DESCRIPTION AND DRAWINGS OR FIGURES The specific embodiments and drawings or figures described herein are supportive and descriptive of the disclosure but are not limiting of the scope of the disclosure as defined by the claims. While some of the best modes and other embodiments for carrying out the claimed disclosure have been described in detail, various alternative designs and embodiments exist for practicing the disclosure defined in the appended claims. Also, the features of the embodiments shown in the drawings or mentioned in the description can not have to be considered as mutually exclusive of one another. Rather, each of the features described in one of the examples of embodiments can be combined with one or more other desired features from other embodiments, resulting in other embodiments that are not described with particularity or reference to the drawings. Therefore, such other embodiments are within the scope of the following claims.

Claims

1. A system for predicting postoperative vertigo in a subject's eye prior to intraocular lens implantation, the system comprising: A controller having a processor and tangible, non-transitory memory on which instructions are recorded; A diagnostic module that communicates with the controller, the diagnostic module being adapted to store preoperative anatomical data of the eye as an eye model; A projection module, which can be selectively executed by the controller, is adapted to determine estimated postoperative variables of the eye based at least in part on the preoperative anatomical data and the intraocular lens; A ray tracing module, which can be selectively executed by the controller, is adapted to calculate the propagation of light through the eye; and The controller is configured to: Preoperative anatomical data of the eye are obtained via the diagnostic module; The estimated postoperative variables of the eye are determined via the projection module, and the estimated postoperative variables are incorporated into the eye model. The ray tracing module is executed to determine the light distribution in the eye model at the corresponding visual angle across a predetermined visual field; and One or more postoperative vertigo parameters are determined, at least in part, based on the light distribution at the corresponding visual field angle.

2. The system as claimed in claim 1, wherein: The ray tracing module tracks the beam of light traveling through the eye; and The one or more postoperative vertigo parameters include a first viewing angle, which is defined as the smallest of the respective visual field angles in which at least a portion of the light beam passing through the pupil of the eye will not pass through the optical zone of the intraocular lens.

3. The system as described in claim 2, wherein: The one or more postoperative vertigo parameters include a second perspective, which is defined as the smallest of the respective visual field angles at which the light beam passing through the pupil will not pass through the optical zone of the intraocular lens.

4. The system as claimed in claim 3, wherein: The one or more postoperative vertigo parameters include a third perspective, which is defined as the smallest visual field angle among the corresponding visual field angles of the intraocular lens that the light beam passing through the pupil would completely miss.

5. The system as claimed in claim 1, wherein: The preoperative anatomical data includes the axial length of the eye.

6. The system of claim 1, wherein: The preoperative anatomical data includes the corresponding positions and contours of the anterior and posterior corneal surfaces of the eye.

7. The system of claim 1, wherein: The preoperative anatomical data includes the position, orientation, and size of the pupil of the eye in a three-dimensional coordinate system, under conditions of clear vision.

8. The system of claim 1, wherein: The estimated postoperative variables for the eye include the corresponding position and orientation of the intraocular lens.

9. The system of claim 1, wherein: The estimated postoperative variables for the eye include the corresponding position and orientation of the pupil and / or iris.

10. The system of claim 1, wherein: The light-tracing module is adapted to track a beam of light that travels backward through the artificial lens until it reaches the retina of the eye; and The beam of light is focused into an infinitesimally small spot on the retina.

11. The system of claim 1, wherein: The ray tracing module is adapted to use a corresponding refractive index in the eye suitable for light with a wavelength of 550 nanometers.

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