Lens system for children with handedness and a method thereof

Abstract

The present disclosure relates to a novel lens system for use of children with handedness (i.e., right- and / or left-handed. The lens system of the present disclosure includes at least one lens associated with a selected eye respectively corresponding to the handedness of the user, namely the eye being closer to the gaze region / point of fixation (e.g., right eye for a right-handed). The at least one lens is configured with regions / zones having different optical properties, i.e., different dioptric power. In particular, a main / primary (central) region having an optical (dioptric) power pre-defined in accordance with the prescription (Rx) of the eye (if any) and one or more secondary zones which may be at the bottom of the lens and having an additional (with respect to the primary region) optical power.

Description

[0001] LENS SYSTEM FOR CHILDREN WITH HANDEDNESS AND A METHOD THEREOF

[0002] TECHNOLOGICAL FIELD

[0003] Embodiments of the presently disclosed subject matter relate generally to optical devices and more specifically to lens systems and methods for correcting the vision of children with handedness.

[0004] BACKGROUND

[0005] Handedness is an individual's preferential use of one hand, / .< ., the dominant hand, due to it being stronger, faster, or better in dexterity. Handedness is often defined by an individual’s writing hand, as it is fairly common for people to prefer to do some tasks with each hand. Right- and left-handers tend to be in opposite postures while writing. Right-handers generally position their paper with the top of it slanted to the left and tilt their heads to the left, thereby emphasizing the right side of their visual space. Left-handers generally position their paper with the top of it slanted to the right and tilt their head to the right, thereby emphasizing the left side of their visual space.

[0006] Accommodation is the process by which the human eye changes optical power to maintain a clear image or focus on an object as its distance varies. In this, distances vary for individuals from the far point namely, the maximum distance from the eye for which a clear image of an object can be seen, to the near point, / .< ., the minimum distance for a clear image. Binocular accommodation is a yoked consensual response in which both eyes change their accommodative state equally to a change in an accommodative stimulus. This consensually suggests that the neural input to accommodation is bilaterally symmetrical. Unequal accommodative stimuli can arise in uncorrected anisometropia (where the two eyes are unequal in optical power) or when the eyes view a near object located away from the midline (in asymmetrical gaze). GENERAL DESCRIPTION

[0007] Due to the slanting of paper (a working surface) and / or tilting of the head for right- and left-handers, a difference in working distances is created between the working surface and the right eye and the left eye. In other words, the gaze regions / fixation points for the right and left eyes are at different distances from the respective eyes on the paper which is typically a word being written (z.e., asymmetric viewing). This causes unequal accommodative demand for each of the eyes. Since the neural input to accommodation is bilaterally symmetrical, sufficient / required aniso-accommodation response may not be achieved and correlative accommodation of both eyes tends to correspond to the lower of the two optical power demands, typically that of the eye which is farther to the gaze region / fixation point. Moreover, since the working distances between each of the eyes and the gaze region are different / unequal, the retinal image in at least one of the eyes is out-of-focus.

[0008] Children are relatively small and have relatively short arms manifesting in relatively short writing distance, z.e., a short working distance between the eye and the respective gaze region resulting in a greater difference in accommodation demands of the two eyes. Since the distance between the eyes and the gaze region is reduced, the same lateral displacement of fixation from the midline leads to a greater difference in the working distances for the two eyes and as a result to greater dioptric difference. This results in unequal intraocular image contrast which may impair fine stereo acuity of the eyes. Moreover, as the distance between the eye and the gaze region / fixation point is reduced, the same lateral displacement of fixation from the midline leads to a greater difference in accommodation demand for the two eyes. The ani so-accommodative demands and the errors of focus associated with the inter-ocular difference of the eyes due to short reading, writing, and similar tasks distances and asymmetric viewing may contribute to retinal image blur and myopia development, particularly in children who adopt unfavorable reading postures.

[0009] It should be noted that the terms “gaze region” and ' fixation point” are used in the present disclosure interchangeably and refer to a region or a point on a working surface (e.g. paper) at which the child gazes / looks on while performing a task (reading or writing, e.g., a written word). The resultant blur may increase as the eccentricity of gaze is increased and the working distance (reading distance) is reduced, and also depends on the posture and position of the head, together with the balance between eye and head movements. Viewing at close distances with persistent head tilt might further contribute to the development of anisometropia. Suppression may occur in one eye as a result of the high level of monocular blur, particularly when head tilt occurs. Evidently, the maintenance of binocular vision is difficult under such circumstances.

[0010] Some researchers investigate the possibility of aligning the children to avoid asymmetric postures. Ergonomics experts, occupational therapy experts, and developmental optometrists oppose the "alignment" of children and argue that they should be allowed to the natural position they have adopted. "Alignment" of children can cause damage on other levels: motor, cognitive, psychological, etc. According to these experts, the body normally adapts to its optimal position, and it is inadvisable to change it.

[0011] In view of the above, there is a need in the art for a lens system suitable for children with handedness (i.e., right- and / or left-handed) adapted for correcting vision by compensating / balancing the non-identical accommodative demand of the eyes in cases of asymmetric viewing to thereby provide similar accommodative demand for both eyes when performing various tasks such as reading and / or writing as well as to provide visual acuity and contrast for both eyes. Further, such a lens system may prevent or at least significantly reduce possible negative developmental effects on children's visual system resulting from non-identical accommodative demand: impaired stereo acuity, unequal image contrast, contribution to retinal image blur, myopia development, anisometropia, and binocular vision difficulties.

[0012] The presently claimed subject matter relates to a novel lens system for use by children with handedness (i.e., right- and / or left-handed). The lens system of the presently claimed subject matter may be configured as spectacle lens(es) or contact lens(es) suitable for performing such tasks as reading and / or writing.

[0013] The lens system of the presently claimed subject matter includes at least one lens associated with a selected eye respectively corresponding to the handedness of the user, namely the eye being brought closer to the gaze region / point of fixation (e.g., right eye for a right-handed) when performing a task. The at least one lens is configured with regions / zones having different optical properties, i.e., different dioptric power. In particular, a main / primary (central) region having an optical (dioptric) power pre-defined in accordance with the vision correction prescription (Rx) of the eye (if any) and one or more secondary zones which may be at the bottom of the lens and having an additional (with respect to the primary region) optical power (dioptric power). This way additional dioptric power is provided to the selected eye, which is closer to the gaze region / point of fixation, as this eye should perform more accommodation, and therefore is out-of-focus with respect to the point of fixation.

[0014] To determine the additional dioptric power needed at the bottom of the lens according to these findings, the working distances from the points of fixation (written word) of the right and left eyes in right- and left-handed children can be measured to enable the calculation of the dioptric gap between these distances. Such a configuration of the lens having one or more secondary zones (e.g. bottom) is beneficial since typically, in the writing / reading process, the paper is located beneath the head of the child such that the child gazes / looks downwards through the bottom secondary zone of the lens towards the fixation point. Light from the fixation point (gaze region) reaches the secondary zone at the bottom of the lens which, in turn, provides additional dioptric power to the closer eye. The lens system of the presently claimed subject matter may generally be used as a preventive measure for individuals developing myopia, anisometropia and impaired stereoacuity, especially in cases of genetic risks.

[0015] The secondary zone which provides additional dioptric power may be symmetrical in the horizontal direction of the lens, or it may be located slightly nasally with respect to the periphery of the lens depending on the area of the lens through which the child gazes while writing / reading, which typically depends on the handedness of the child namely, different for right- and left-handed children. Provided that the distance prescription of the child is proper, such an increase in dioptric power at the secondary zone(s) of the lens associated with the closer eye allows for a proper vision for both eyes, and better coordination between the two eyes, while preserving the child’s natural asymmetrical position (as recommended by experts) which is the underlying cause for a difference in the working distances between both eyes and the fixation point / gaze region on the paper. Therefore, according to one broad aspect of the present disclosure, there is provided a personalized lens system for a child having a certain handedness, the lens system comprising at least one lens being configured and operable to correct vision according to the handedness of the child, wherein the lens corresponding to a right eye for a right-handed child or the lens corresponding to a left eye for a left-handed child defines an optical property profile having (1) a central primary optical zone and (2) a secondary zone having a bottom and top regions, wherein at least a part of the bottom region is configured to provide an additional dioptric power as compared to that of the central primary optical zone.

[0016] In some embodiments, the central primary optical zone has an optical correction according to the Rx of the corresponding eye.

[0017] In some embodiments, the central primary optical zone has no refractive power.

[0018] In some embodiments, the at least part of the bottom region is configured to provide the additional dioptric power defining an area being symmetrical in the horizontal direction.

[0019] In some other embodiments, the at least part of the bottom region is configured to provide the additional dioptric power defining an area being non-symmetrical in the vertical direction.

[0020] In some embodiments, the at least part of the bottom region is configured to provide the additional dioptric power defining an area in between about 15° to about 25° below the horizontal line of gaze. As used herein the term "about" refers to plus or minus 10 percent.

[0021] In some embodiments, the additional dioptric power is determined according to at least one of a child's age or age group, a Harmon distance, and a child's height. A correlation between the height of the child (maybe also the age) and the added dioptric power at the lower part of the lens corresponding to the closer eye may be established. For example, the shorter the child the higher the added dioptric power can be.

[0022] In some embodiments, the additional dioptric power is determined using statistical methods based on at least one of the child's age or age group, the Harmon distance, and the child's height. In some embodiments, the additional dioptric power is in the range of about +0. ID to +0.4D.

[0023] In some embodiments, the at least one lens comprises at least one spectacle lens or at least one contact lens.

[0024] In some embodiments, the lens system also includes a second lens, the second lens may have a single vision optical property profile.

[0025] According to another broad aspect of the present disclosure, there is provided a method for designing a personalized lens system for a child having a certain handedness, the method comprising: obtaining data indicative of vision properties (e.g., a prescription (Rx) if any) and a handedness of a child, and at least one of the following parameters: a child's age or age group, a Harmon distance, and a child's height; based on said obtained data, generating data indicative of a personalized lens optical property profile by carrying out the following: providing configuration data for a central primary optical zone of at least one lens; determining an additional dioptric power that enables allowing at least one of the same accommodative demand, visual acuity, and contrast for both eyes of the child; and generating configuration data for a secondary optical zone in at least a part of a bottom region of the lens having the additional dioptric power.

[0026] In some embodiments, the central primary optical zone of the at least one lens is configured to have an optical correction according to the Rx of the corresponding eye.

[0027] In some embodiments, the central primary optical zone of the at least one lens is configured to have no refractive power. In some embodiments, determining the configuration data for the secondary optical zone having the additional dioptric power comprises determining an area and position of said secondary optical zone on the lens to which the additional power is applied.

[0028] In some embodiments, the method also includes correlating between the additional dioptric power and at least one of the following parameters: a child's age or age group, a Harmon distance, and a child's height. The correlation may be carried out by using statistical methods based on at least one of the child's age or age group, the Harmon distance, and the child's height. According to another broad aspect of the invention, the invention provides spectacles for a child having a certain handedness, comprising: a first lens corresponding to a left eye for a right-handed child or to a right eye for a left-handed child; and a second lens corresponding to a right eye for a right-handed child or to a left eye for a left-handed child, said second lens having an optical property profile defined by (1) a central primary optical zone configured with a dioptric power, and (2) at least one secondary zone accommodated within at least one peripheral portion of said second lens, wherein at least a part of a bottom region of the peripheral portion is configured to provide an additional power, as compared to the said dioptric power of the central primary optical zone, for compensating the non-identical accommodative demand of the eyes of the child in asymmetric viewing tasks.

[0029] According to yet another broad aspect of the present disclosure, there is provided a processing unit for providing a personalized lens optical property profile, the processing unit comprising: a data input utility being configured and operable to receive a childrelating data comprising: data indicative of vision properties (a certain prescription (Rx) and a handedness of the child and at least one of the following parameters: a child's age or age group, a Harmon distance and a child's height; a data analyzer being configured and operable to analyze the child-related data and generate configuration data for a central primary optical zone of at least one lens in accordance with the vision properties of the corresponding eye of the child (e.g., to have an optical correction, if any, according to the Rx of the corresponding eye), and determine an additional dioptric power required to allow the same accommodative demand, visual acuity and contrast for both eyes of the child; and generate configuration data for a secondary optical zone with the additional dioptric power; and a data output utility being configured and operable to provide output data indicative of a personalized lens optical property profile defining the central primary optical zone and the secondary zone with the additional dioptric power.

[0030] BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to better understand the subject matter that is disclosed herein and to exemplify how it may be carried out in practice, embodiments will now be described, by way of non-limiting examples only, with reference to the accompanying drawings, in which: Figs. 1A-1B illustrate a difference in paper positions and postures of right- and left-handed individuals;

[0032] Fig. 2A - 2C graphically illustrate Harmone distances as a function of age, as well as the same for right-handed and left-handed children.

[0033] Fig. 3A-3H show schematic illustrations of different possible personalized lens systems of the presently disclosed subject matter;

[0034] Fig. 31 shows a possible personalized lens of the presently disclosed subject matter;

[0035] Fig- 4 shows a perspective view of a lens configured based on the principles of the presently disclosed subject matter;

[0036] Figs. 5A and 5B show respectively, a dioptric power addition map and dioptric power distribution of the lens of the presently disclosed subject matter.

[0037] Fig. 6 exemplifies, by way of a flow chart, a method of the presently disclosed subject matter for designing a personalized lens system for a child having a certain handedness; and

[0038] Fig. 7 shows a functional block diagram of a processing unit of the presently disclosed subject matter for providing a personalized lens optical property profile.

[0039] DETAILED DESCRIPTION OF EMBODIMENTS

[0040] One or more specific and / or alternative embodiments of the present disclosure will be described below with reference to the drawings, which are to be considered in all aspects as illustrative only and not restrictive in any manner. It shall be apparent to one skilled in the art that these embodiments may be practiced without such specific details. In an effort to provide a concise description of these embodiments, not all features or details of an actual implementation are described at length in the specification. Elements illustrated in the drawings are not necessarily to scale, or incorrect proportional relationships, which are not critical. Emphasis instead being placed upon clearly illustrating the principles of the invention such that persons skilled in the art will be able to make and use the augmented terrestrial communication hereof, once they understand the principles of the subject matter disclosed herein. This invention may be provided in other specific forms and embodiments without departing from the essential characteristics described herein.

[0041] Any reference in the specification to a method should be applied mutatis mutandis to a device or system capable of executing the method and / or to a non-transitory computer-readable medium that stores instructions for executing the method.

[0042] Any reference in the specification to a system or device should be applied mutatis mutandis to a method that may be executed by the system, and / or may be applied mutatis mutandis to a non-transitory computer-readable medium that stores instructions executable by the system.

[0043] Any combination of any module or unit listed in any of the figures, any part of the specification, and / or any claims may be provided.

[0044] The specification and / or drawings may refer to a processor. The processor may be a processing circuitry. The processing circuitry may be implemented as a central processing unit (CPU) and / or a graphics processing unit (GPU), and / or one or more other integrated circuits such as application-specific integrated circuits (ASICs), field programmable gate arrays (FPGAs), full-custom integrated circuits, or a combination of such integrated circuits. A computerized system may include one or more processors and may also include additional units or components such as memory units, communication units, and the like.

[0045] Reference is made to Figs. 1A-1B showing paper positions and postures of right- and left-handed individuals. The correct paper position and tilt enable the child to handwrite comfortably while being able to see what he / she is writing. It also allows the non-writing hand to move the paper up the table so that the writing hand's elbow can stay in the same position. With the non-writing hand moving the paper up the table the distances from the right and left eyes to the gaze region respectively (e.g., writing line) remain the same which means eye movements are less, helping to make the writing experience less tiring and stressful. When the paper is positioned and tilted correctly, with their writing hand under the writing line, as can be seen in Fig. IB, they are also able to see more easily what they have just written and where to place the next letter, word, or section of text on the page. As mentioned above, during this process the child typically gazes through the bottom portion of the lens. A typical paper tilt angle can generally be anywhere between 20 to 45 degrees with respect to a midline axis M anti-clockwise for right-handed writers and 20 to 45 degrees with respect to the midline axis M clockwise for left-handed writers.

[0046] As also mentioned above, the slanting of the working surface (e.g., a paper) and / or tilting of the head gives rise to different working distances between the working surface and the right eye and the left eye causing unequal accommodative demand for each of the eyes.

[0047] The inventors of the present disclosure have collected data including various parameters of right- and left-handed individuals of different age groups. This data demonstrates an inversed correlation between the child’s age and a dioptric gap between his / hers right and left eyes. The term "dioptric gap" used herein refers to a difference in the accommodation demand (measured in diopters) between the two eyes. Dioptric gap represents the difference in the accommodation requirements from each eye (one eye has a stronger or weaker accommodative demand than the other).

[0048] Thus, the younger the child the larger is the dioptric gap value. This inversed correlation stems from the fact that respective working distances of the left and right eyes are shorter in younger individuals (compared to older ages) which results in a greater difference in accommodation demands for each of the two eyes.

[0049] Harmon distance is defined as fist to elbow length and considered as the optimal working distance for most people for performing visually close tasks such as reading, writing, working at a computer. This distance helps ensure that the eyes are not strained and that the viewing angle is comfortable. At this distance, the eyes should not have to over-converge (move towards the nose), and it supports good posture, reducing the risk of eye strain or discomfort.

[0050] The following tables 1-4 show the collected data relating to right- and left- handed children in different age groups. For each age group, average values were calculated for

[0051] (i) difference in a working distance between right and left eyes from fixation point, and

[0052] (ii) dioptric gap between right and left eyes. Tables 5 and 6 show Harmon distance values for right- and left-handed children, respectively, at different ages. Table 1 shows the data for right-handed children of a first (younger) age group - ages in the range of 6-6.5 years old. Table 2 shows right-handed children at of a second (older) age group - ages in the range of 8-15 years old.

[0053]

[0054] As can be seen in tables 1 and 2, the difference in average distances of the right and left eyes from the fixation point between the first and second age groups is about 4.5 mm which is relatively small. However, it appears that this relatively small difference in the average working distance corresponds to a relatively large difference (more than 50%) of the average dioptric gap, which is about 0.119 D, between the two age groups. This is indicative of that younger children have greater difference in accommodation demands of the two eyes compared to children at older ages thus emphasizing the importance of providing additional dioptric power to the eye being closer to the gaze region in younger children.

[0055] Table 3 shows left-handed children of a first (younger) age group - ages in the range of 6-6.5 years old.

[0056] Table 4 shows left-handed children at of a second (older) age group - ages in the range of 8-15 years old.

[0057] As can be seen, similarly to right-handed children, in left-handed children, the difference of average distances of the right and left eyes from the fixation point between the first and second age groups is relatively small - 6mm, while the difference between average dioptric gap between the two age groups is relatively large - about 0.2378 D.

[0058] Table 5 summarizes Harmon distances of right-handed children at ages of 6-15.

[0059] Table 6 summarizes Harmon distances of left-handed children at ages of 6-15

[0060] Reference is made to Figs. 2A to 2C, wherein Figs. 2A and 2B show a graphical representation of the data in tables 5 and 6, respectively, and Fig. 2C graphically illustrates the Harmon distance as function of age in individuals between the ages of 5- 15. In the figures, dotted lines 71n, 72n, and 73n are linear normalizations of curves 71, 72, and 73, respectively. As can be seen in the figures and in tables 5 and 6, there exists a correlation between a person’s age and his / hers Harmon distance, namely the Harmon distance increases with age. As the child grows, his / her height and Harmon distances also grow. Consequently, the child’s working distance also grows as the child grows older.

[0061] It should be understood that the same absolute value of a difference in the working distance for the right and left eyes for children and adults actually corresponds to a higher meaningful working distance difference for children, as compared to adults, because of a smaller Harmon distance of children. This results in a larger dioptric gap in children thus emphasizing the importance of additional dioptric power to the eye being closer to the gaze region in younger children. Accordingly, the fact that younger children are characterized by a larger dioptric gap emphasizes the need to provide additional dioptric power to the eye being closer to the gaze region as compared to the eye being further from the gaze region, for compensating / balancing the non-identical accommodative demand of the eyes.

[0062] The present invention provides a novel lens configuration enabling compensation in the dioptric gap caused by the working distance difference for right-handed and lefthanded children.

[0063] Reference is made to Fig. 3A-3G showing schematic drawings of different personalized lens systems 100A-100G respectively of the presently disclosed subject matter aimed to be used by an individual (e.g., a child) having a certain handedness namely, right- and / or left-handed individuals. The lens systems 100A-100G include at least one lens 101A-101G being configured and operable to correct vision according to the handedness of the individual / child. The at least one lens can be in the form of a spectacle lens or contact lens. The lenses 101A-101G correspond to an eye 103A which is closer to a fixation point FP (e.g., a word being written). In particular, the eye 103A that is closer to the fixation point FP is the right eye for a right-handed child or the left eye for a left-handed one. Although the lenses 101A-101G are shown in the figure as circular lenses, the presently disclosed subject matter is not limited to this configuration and the lenses 101A-101G may have different sizes or shapes depending on the frame of the lens.

[0064] The lenses 101A-101G define an optical property profile having a central primary optical zone 102. In some embodiments, the central primary optical zone 102 has an optical correction according to the Rx of the corresponding eye 103 A, / .< ., having a dioptric power P, and a secondary zone PZ located at a peripheral portion of the lens 101. In some other embodiments, the central primary optical zone 102 is piano, namely has no dioptric / refractive power (Rx =0).

[0065] In some embodiments, the secondary zone PZ may have bottom and top regions 102A and 102A', respectively. At least a part of the bottom region 102A-102G is configured to provide an additional dioptric power P ’ with respect to the dioptric power P of the central primary optical zone 102 such that the at least a part of the bottom region 102A-102G has a dioptric power of PT = P + P The additional dioptric power P ’ may be in the range of +0.1D to +0.4D. The unique configuration of the lens with additional dioptric power balances the non-identical accommodative demand of the two eyes, thus allowing the same visual acuity and contrast for both eyes, as well as better coordination between the two eyes, and may also prevent or at least significantly reduce the development of possible visual defects such as myopia, anisometropia, and binocular vision difficulties. Optionally, and in some embodiments preferably, the top region 102A' of the secondary zone PZ is an integral part of the central primary optical zone 102 and has an optical correction according to the Rx of the corresponding eye 103A (Rx of the central primary optical zone 102).

[0066] As illustrated in Fig. 3A, in operation, the user gazes towards the fixation point FP (gaze region) which is typically located beneath the head such that light L emerging from the fixation point FP interacts with the bottom region 102A-102G of the lens 101, which in turn, applies the dioptric power PT = P + P’ on the light L thereby at least partially eliminating the dioptric difference between the two eyes, defocusing effects of the corresponding eye and balancing the non-identical accommodative demand of the two eyes.

[0067] Optionally, and in some embodiments preferably, the at least a part of the bottom region 102A-102G is configured with an additional dioptric power defining an area being symmetrical in the vertical direction. Namely, the bottom region 102A-102E is symmetrical with respect to a vertical symmetry axis O of the lens 101. As shown in Figs. 3A and 3B, the bottom region 102A-102B may be a peripheral region partially located on portion 104 of a circumference / boundary of the lens 101. Alternatively, as shown in Fig. 3C the bottom region 102C may be spaced-apart from the circumference / boundary of the lens 101. As also shown in Figs. 3A-3G the bottom region 102A-102G may have any geometrical shape including, inter alia, concaved, truncated, circular, and oval. As shown in Figs. 3F-3G, the bottom region 102A-102G is configured with an additional dioptric power defining an area being non-symmetrical in the vertical direction. Namely, the bottom region 102F-102G may be located non-symmetrically with respect to the vertical symmetry axis O, i.e., located slightly nasally (closer to the nose). This special configuration is particularly useful for children who tend to gaze through a peripheral region of the lens located away from the center of the lens. In some embodiment, the bottom region 102A-102G may be configured with a uniform distribution of the additional dioptric power across the area of the bottom region 102A-102G. Alternatively, the bottom region 102A-102G may be configured with a continuously varying additional dioptric power in the vertical direction, z.e., in a direction along the symmetry axis O, such continuously varying additional dioptric power can be in the range of 0.125 [D] to 0.60 [D] .

[0068] In other embodiments, the bottom region 102A-102G may be configured with discrete varying additional dioptric power. That is, the bottom region 102A-102G may include a plurality of discrete sub-regions / segments, each such sub-region having a different additional dioptric power. For example, as shown in Fig. 3H, the bottom region 102B includes a plurality of sub-regions SI, S2, SN arranged horizontally, z.e., substantially perpendicular to the symmetry axis O. Each sub-region has a corresponding different additional dioptric power. It should be noted the bottom region 102H may include sub-regions of any shape and size.

[0069] As shown in Fig. 31, the lens 1021 can be a free-form lens having a continuously varying dioptric power in the vertical direction, z.e., in a direction along the symmetry axis O, such continuously varying additional dioptric power can be in the range of 0.125 [D] to 0.60 [D],

[0070] In some embodiments, the additional power is determined according to at least one of a child's age, a Harmon distance, or a child's height. Alternatively, or additionally, the additional power can be determined by using statistical methods based on at least one of the child's age or age group, the Harmon distance, and the child's height.

[0071] In some embodiments, as illustrated in Fig. 3A above, the lens system 100 further includes a second lens 100A' for the left eye of a right-handed child or the right eye of a left-handed one. The second lens 100A' corresponds to the second more distant eye 103B from the fixation point FP. The second lens 100A' may be a conventional lens having a single vision optical property profile determined in accordance with the prescription (Rx).

[0072] It should be noted that the prescription (Rx) for the optical properties of the second lens 100A' can be similar to or different from that of the central primary optical zone 102 of the lens 100A i.e., the second lens 100A' has the same dioptric power P or a different dioptric power as compared to zone 102 of the lens 100A or no dioptric power at all (piano lens). This is because the optical properties of the lens that is farther from the fixation point and does not include additional power at the lower part are according to the prescription of the child for that specific eye. It is not necessarily the same as the prescription for the other eye. For example, a child can have a prescription of 2D for the right eye and 3D for the left eye.

[0073] Some examples of determining the suitable lens configuration for right- and lefthanded children and the optical properties thereof are demonstrated herein. In a specific and non-limiting example, a 6-year-old right-handed boy, who is 1.17m tall and has a Harmon distance of 24 cm. The distance between the right eye from a written word is 25 cm and between the left eye from the written word is 27 cm. The difference in eye distances from the written letter is 2 cm, and the difference in diopters (i.e., dioptric gap) is 0.3D. When the child writes, his accommodative system will operate according to the more distant eye, i.e., 4D of the accommodation (=100cm / 25cm). The accommodative system tends to prefer having a quality image while investing minimal effort, so it will operate according to the more distant eye, which requires less accommodation for the focused image on the retina, compared to the closer one. In this case, the closer eye will generate a non-optimal image on the retina, with a dioptric gap (i.e., the gap between the accommodation demand of the two eyes) of about 0.3D. In this case, this child needs an additional dioptric power of about +0.3D at the bottom region 102A-102G of the lens 101 which corresponds to the closer eye (right eye in this specific example), in order to balance the quality of the images on the retinas and allow better binocular vision and better coordination between the two eyes.

[0074] When the child grows and becomes 11 years old, he is 1.45m tall and his Harmon distance is 34 cm. With the same head position as at a younger age, the distances this time from the written word are 34 cm for the right eye and 36 cm for the left eye. The difference in eye distances from the written letter is still 2 cm, but the difference in diopters is 0.2D. That is, the relative distance between the eyes and the written word is maintained, but the corresponding dioptric value is reduced and therefore a lower additional dioptric power of about +0.2D will be required at the bottom peripheral zone of the bottom region 102A- 102G of the lens 101 in order to balance the quality of the images on the retinas and allow better binocular vision and better coordination between the two eyes. In a further non-limiting example, a 7-y ear-old right-handed boy, who is 1.25m tall and has a Harmon distance of 18 cm. The distance between the right eye from the written word is 18 cm and between the left eye from the written word is 20 cm. The difference in eye distances from the written letter is 2 cm, and the difference in diopters is 0.55D. When the child writes, his accommodative system will operate according to the more distant eye, / .< ., 5D of the accommodation (=100cm / 20cm). The accommodative system tends to prefer having a quality image while investing minimal effort, so it will operate according to the more distant eye, which requires less accommodation for the focused image on the retina, compared to the closer one. In this case, the closer eye will generate a non-optimal image on the retina, with a dioptric gap (i.e., the gap between the accommodation demand of the two eyes) of about 0.55D. In this case, this child needs an additional dioptric power of about +0.4D at the bottom secondary zone of the lens in front of the closer eye (right eye in this specific example), in order to balance the quality of the images on the retinas and allow better binocular vision and better coordination between the two eyes.

[0075] When the child grows and becomes 11 years old, he is 1.45m tall and his Harmon distance is 22 cm. With the same head position as at a younger age, the distances this time from the written word are 22 cm for the right eye and 24 cm for the left eye. The difference in eye distances from the written letter is still 2 cm, but the difference in diopters is 0.38D. That is, the relative distance between the eyes and the written word is maintained, but its dioptric value is reduced and therefore a lower additional dioptric power of about +0.2D will be required at the bottom peripheral zone of the right lens in order to balance the quality of the images on the retinas and allow better binocular vision and better coordination between the two eyes.

[0076] Reference is made to Fig. 4 showing a perspective view of the lens 101 of the presently disclosed subject matter. As shown, an angle between the horizontal line of gaze Li and the line of gaze L2 associated with bottom region 102B may be between about 15° to about 25°. Thus, in some embodiments, the at least a part of the bottom region 102A- 102G is configured to provide an additional dioptric power defining an area between about 15° to about 25° below the horizontal line of gaze Li. Reference is made to Fig. 5A and 5B, showing respectively, a dioptric power addition map and dioptric power distribution as a function of distance from optical center OC of the lens along a vertical meridian VM thereof. In this non-limiting example, the additional dioptric power in the secondary zone reaches a maximal value of 0.4 [D] at an angle of about 25° below the horizontal line of gaze.

[0077] Reference is made to Fig. 6, showing a functional flow chart of a method 300 for designing a personalized lens system for a child having a certain handedness of the presently disclosed subject matter. Method 300 may also include obtaining in 301, a child-relating data comprising: data indicative of vision properties (prescription (Rx)), a handedness of a child, and at least one of the following parameters: a child's age or age group, a Harmon distance, and a child's height.

[0078] In some embodiments however, the central primary zone may have dioptric / refractive power. Generating in 302 configuration data for a central primary optical zone of at least one lens in accordance with the vision properties of the corresponding eye of the child. The central primary optical zone can be configured to have an optical correction according to the Rx of the corresponding eye which is the eye that is closer to the fixation point (e.g., a word being written) namely, a right eye for a right-handed child or a left eye for a left-handed. Alternatively, the central primary optical zone can be configured to have no dioptric / refractive power at all. Determining in 303 an additional dioptric power required to enable the same accommodative demand, visual acuity, and contrast for both eyes. In some embodiments, determining the additional dioptric power in 303 also includes determining in 304 an area so dimensioned as to correspond to 15 degrees to 25 degrees of gaze and its position on the lens to which the additional power is applied. Method 300 also includes generating in 307 configuration data for a secondary zone with the additional dioptric power.

[0079] In some embodiments, before configuring a secondary zone with the additional dioptric power in 307, the method 300 may include correlating in 305 between the additional dioptric power and at least one of the following parameters: a child's age or age group, a Harmon distance, and a child's height. In some embodiments, the correlation in 307 also includes using statistical methods based on at least one of the child's age or age group, the Harmon distance, and the child's height. Reference is made to Fig. 7, showing a functional block diagram of a processing unit 400 for providing a personalized lens optical property profile. In general, processing unit 400 may be a processor, a controller, a microcontroller, or any kind of integrated circuit. Control unit 300 is configured generally as a computing / electronic utility including inter alia such utilities as a data input utility 400A, a data analyzer 400D, and a data output utility 400B and may further include or be associated with a memory 400C ( / .< ., a non-volatile computer-readable medium) for storing the input / output data, a database, or the computer program.

[0080] The database may be a cloud-based system. In an example, the cloud-based system may be a distributed blockchain system, wherein a number of parties (e.g., manufacturer, recycler, retailer) have access to the distributed ledger. The latter is a type of Internet-based computing that provides shared computer processing resources and data (such as servers, storage, and applications) to computers and other devices through the computer network (or communication network), such as the Internet. Cloud computing and storage solutions provide users and enterprises with various capabilities to store and process their data in either privately owned or third-party data centers that may be located far from the user-ranging in distance from across a city to across the world. Thus, the present disclosure provides for using the cloud computing technique, according to which a central data analyzer (software) is used to receive the sensing data from multiple products' storage locations and uses these multiple data sources for optimizing the above- mentioned identification of the product types and product status monitoring (e.g. utilizing self-learning modes, models' optimization, etc.).

[0081] Memory 400C may be integrated within processing unit 400 or may be an external storage device accessible by processing unit 400. The software may be downloaded to processing unit 400 in electronic form, over a network, for example, or it may alternatively be provided on tangible media, such as optical, magnetic, or electronic memory media. The computer program described above may be intended to be stored in memory 400C, or in a removable memory medium adapted to cooperate with a reader of the processing unit 400, comprising instructions for implementing the method as will be described below. More specifically, the computer program may be in communication with an interface to receive order and time data. Unless specifically stated otherwise, as apparent from the following discussions, it is appreciated that throughout the specification discussions utilizing terms such as "determining" , "processing" or the like, refer to the action and / or processes of a computer that manipulates and / or transforms data into other data. Also, operations in accordance with the teachings herein may be performed by a computer specially constructed for the desired purposes, or by a general -purpose computer specially configured for the desired purpose by a computer program stored in a computer-readable storage medium.

[0082] The data input utility 400A is configured and operable to receive certain childrelating data comprising: data indicative of vision properties (e.g., vision correction prescription (Rx)), a handedness of the child, and at least one of the following parameters: a child's age or age group, a Harmon distance, and a child's height. The data input utility 400A may comprise a communication interface being appropriately configured for connecting the data analyzer 400D, via wires or wireless signal transmission (e.g., via communication network(s)), to either a measurement module supplying the parameters mentioned above or to external memory (database) where such data have been previously stored. The communication interface may be a separate utility from processing unit 400 or may be integrated therewithin. When the communication interface is a separate unit from processing unit 400, processing unit 400 may comprise a transceiver permitting it to be connected to the communication interface and to transmit and / or receive data. When the communication interface is integrated within processing unit 400, it may be included in the data input utility 400 A and the data output utility 400B of processing unit 400.

[0083] The data analyzer 400D is configured and operable to analyze the child-related data and generate configuration data for a central primary optical zone of at least one lens in accordance with the vision properties of the corresponding eye of the child (e.g., to have an optical correction according to the Rx of the corresponding eye), and determine an additional dioptric power required to allow the same accommodative demand, visual acuity, and contrast for both eyes of the child. The data analyzer 400D is also adapted for generating configuration data for a secondary zone with the additional dioptric power.

[0084] The data output utility 400B is configured and operable to provide output data indicative of a personalized lens optical property profile defining the central primary optical zone having an optical correction according to the Rx of the corresponding eye and a secondary zone with the additional dioptric power.

[0085] The utilities of the processing unit 400 may thus be implemented by suitable circuitry and / or by software and / or hardware components including computer readable code configured for receiving a calculated optical design profile being indicative of a specific patient's correction namely, the optical properties of the secondary zone and for processing the data to generate a physical representation data of the optical property profile. The features of the present invention may include a general-purpose or specialpurpose computer system including various computer hardware components. Features within the scope of the present invention also include computer-readable media for carrying out or having computer-executable instructions, computer-readable instructions, or data structures stored thereon. Such computer-readable media may be any available media, which are accessible by a general -purpose or special-purpose computer system. In this description and the following claims, a "processing unit" is defined as one or more software modules, one or more hardware modules, or combinations thereof, which work together to perform operations on electronic data. The physical layout of the modules is not relevant. The processing unit 400 may be configured as an electronic module for collecting, processing data, and optionally sending instructions to a system being capable of creating the optical property profile. In some embodiments, processing unit 400 is configured and operable to calculate an optical design profile being indicative of a specific patient's correction.

[0086] The term "processing unit" should be expansively construed to cover any kind of electronic device with data processing capabilities, including, by way of non-limiting example, personal computers, servers, computing systems, communication devices, processors (e.g. digital signal processor (DSP), microcontrollers, field programmable gate array (FPGA), application specific integrated circuit (ASIC), etc.) and other electronic computing devices. The control unit may comprise a general -purpose computer processor, which is programmed in software to carry out the functions described hereinbelow. Also, operations in accordance with the teachings herein may be performed by a computer specially constructed for the desired purposes or by a general-purpose computer specially configured for the desired purpose by a computer program stored in a computer-readable storage medium. The different elements of the processing unit (electronic unit and / or mechanical unit) are connected to each other by wires or are wireless. The software may be downloaded to the processing utility in electronic form, over a network, for example, or it may alternatively be provided on tangible media, such as optical, magnetic, or electronic memory media. Alternatively, or additionally, some or all of the functions of the processing unit may be implemented in dedicated hardware, such as a custom or semi-custom integrated circuit, or a programmable digital signal processor (DSP).

[0087] The terms "control unit" and "processor utility" are used herein interchangeably and refer to a computer system, state machine, processor, or the like, designed to perform arithmetic or logic operations using logic circuitry that responds to and processes the instructions that drive a computer. The techniques and system of the presently disclosed subject matter can find applicability in a variety of computing or processing environments, such as a computer or process-based environments. The techniques may be implemented in a combination of software and hardware. The techniques may be implemented in programs executing on programmable machines such as stationary computers being configured to obtain raw log data, as has also been described above. Program code is applied to the data entered using the input device to perform the techniques described and to generate the output information. The output information can then be applied to one or more output devices. Each program may be implemented in a high-level procedural or object-oriented programming language to communicate with a processed-based system. However, the programs can be implemented in assembly or machine language, if desired.

[0088] In other embodiments, the technique of the presently disclosed subject matter can be utilized over a network computing system and / or environment. Several computer systems may be coupled together via a network, such as a local area network (LAN), a wide area network (WAN), or the Internet. Each method or technique of the presently disclosed subject matter as a whole or a functional step thereof could be thus implemented by a remote network computer or a combination of several. Thus, any functional part of processing unit 400 can be provided or connected via a computer network. In addition, the control unit can also remotely provide processor services over a network. Each such program may be stored on a storage medium or device, e.g., compact disc read-only memory (CD-ROM), hard disk, a magnetic diskette, or similar medium or device, that is readable by a general or special purpose programmable machine for configuring and operating the machine when the storage medium or device is read by the computer to perform the procedures described in this document. The system may also be implemented as a machine-readable storage medium, configured with a program, where the storage medium so configured causes a machine to operate in a specific and predefined manner.

[0089] Relative terms such as "lower," "upper," "horizontal," "vertical," "above," "below," "up," "down," "top" and "bottom", as well as derivatives thereof e.g., "horizontally," "downwardly," "upwardly," etc.), and similar adjectives in relation to the orientation of the described elements / components refer to the manner in which the illustrations are positioned on the paper, not as any limitation to the orientations in which these elements / components can be used in actual applications.

[0090] It should also be understood that throughout this disclosure, where a process or method is shown or described, the steps / acts of the method may be performed in any order and / or simultaneously, and / or with other steps / acts not illustrated / described herein unless it is clear from the context that one step depends on another being performed first. In possible embodiments, not all of the illustrated / described steps / acts are required to carry out the method.

Claims

CLAIMS:

1. A personalized lens system of a child having a certain handedness, the lens system comprising a lens being configured and operable to correct vision according to the handedness of the child, wherein said lens corresponds to a right eye for a right-handed child or the lens corresponding to a left eye for a left-handed child, and has an optical property profile defining (1) a central primary optical zone, and (2) at least one secondary zone accommodated within at least one peripheral portion of said lens, wherein at least a part of a bottom region of the peripheral portion is configured to provide an additional dioptric power, as compared to the central primary optical zone, for compensating nonidentical accommodative demand of the right and left eyes of the child in asymmetric viewing tasks.

2. The lens system of claim 1, wherein the central primary zone has a dioptric power according to an Rx of a corresponding eye.

3. The lens system of claim 1, wherein the central primary zone has no dioptric power.

4. The lens system of any one of the preceding claims, wherein the at least part of the bottom region is configured to provide said additional dioptric power defining an area being symmetrical in the vertical direction.

5. The lens system of any one of claims 1 to 3, wherein the at least part of the bottom region is configured to provide said additional dioptric power defining an area being non- symmetrical in the vertical direction.

6. The lens system of any one of the preceding claims, wherein the at least a part of the bottom region that is configured to provide an additional dioptric power defines an area in between about 15° to about 25° below the horizontal line of gaze.

7. The lens system of any one of the preceding claims, wherein the additional dioptric power is determined according to at least one of a child's age or age group, a Harmon distance, and a child's height.

8. The lens system of claim 7, wherein the additional dioptric power is determined using statistical methods based on at least one of the child's age or age group, the Harmon distance, and the child's height.

9. The lens system of any one of the preceding claims, wherein the additional dioptric power is in the range of about +0.1D to +0.4D.

10. The lens system of any one of the preceding claims, wherein said lens is configured as a spectacle lens or as a contact lens.

11. The lens system of any one of the preceding claims, further comprising a second lens.

12. The lens system of claim 11, wherein the second lens has a single vision optical property profile.

13. Spectacles for a child having a certain handedness, comprising: a first lens corresponding to a left eye for a right-handed child or to a right eye for a left-handed child; and a second lens corresponding to a right eye for a right-handed child or to a left eye for a left-handed child, said second lens having an optical property profile defined by (1) a central primary optical zone configured with a dioptric power, and (2) at least one secondary zone accommodated within at least one peripheral portion of said second lens, wherein at least a part of a bottom region of the peripheral portion is configured to provide an additional power, as compared to the said dioptric power of the central primary optical zone, for compensating the non-identical accommodative demand of the eyes of the child in asymmetric viewing tasks.

14. The spectacles of claim 13, wherein said dioptric power of the central primary optical zone is substantially 0 or correspond to respective non-zero prescription (Rx) of a respective eye vision correction.

15. The spectacles of claim 13 or 14, wherein the first lens has an optical power corresponding to a respective prescription of a respective eye vision correction.

16. The spectacles of claim 13 or 14, wherein the first lens has substantially zero refractive power.

17. The spectacles of any one of claims 13 to 16, wherein the at least part of the bottom region is configured to provide the additional dioptric power defining an area being symmetrical in the vertical direction.

18. The spectacles of any one of claims 13 to 16, wherein the at least part of the bottom region is configured to provide the additional dioptric power defining an area being non- symmetrical in the vertical direction.

19. The spectacles of any one of claims 13 to 18, wherein the at least part of the bottom region that is configured to provide the additional dioptric power defines an area in between about 15° to about 25° below the horizontal line of gaze.

20. A method for designing a personalized lens system for a child having a certain handedness, the method comprising: obtaining a child-relating data comprising data indicative of vision properties of a child, a handedness of the child, and at least one of the following parameters: a child's age or age group, a Harmon distance, and a child's height; analyzing the child-related data and generating configuration data for a lens corresponding to a right eye for a right-handed child or to a left eye for a left-handed child, by carrying out the following: generating configuration data for a central primary optical zone of said lens in accordance with said vision properties of the corresponding eye of the child; and determining an additional dioptric power required to provide at least one of the same accommodative demand, visual acuity, and contrast for both eyes; and generating configuration data for a secondary zone with the additional dioptric power in at least a part of a bottom region of the lens.

21. The method of claim 20, wherein the vision properties of the child comprise a prescription (Rx) of the child.

22. The method of claim 20 or 21, wherein the central primary optical zone of the at least one lens is configured to have a dioptric power according to prescription (Rx) of the corresponding eye.

23. The method of claim 20 or 21, wherein the central primary optical zone of the at least one lens is configured to have no refractive power.

24. The method of any one of claims 20 to 23, wherein determining the additional dioptric power comprises determining an area and its position on the lens to which the additional dioptric power is applied.

25. The method of any one of claims 20 to 24, further comprising correlating between the additional dioptric power and at least one of the following parameters: a child's age or age group, a Harmon distance, and a child's height.

26. The method of claim 25, wherein the correlation comprises using statistical methods based on at least one of the child's age or age group, the Harmon distance, and the child's height.

27. A processing unit for providing a personalized lens optical property profile, the processing unit comprising: a data input utility being configured and operable to receive a child-relating data comprising data indicative of vision properties of a child, a handedness of a child and at least one of the following parameters: a child's age or age group, a Harmon distance, and a child's height, a data analyzer being configured to analyze the child-related data and generate configuration data for a lens corresponding to a right eye for a right-handed child or to a left eye for a left-handed child, by determining a central primary optical zone of the lens in accordance with the vision properties of the corresponding eye of the child, determining an additional dioptric power required to allow the same accommodative demand, visual acuity and contrast for both eyes; and generate configuration data for a secondary optical zone with said additional dioptric power, as compared to the central primary optical zone, in at least a apart of a bottom region of the lens; and a data output utility being configured to provide output data indicative of a personalized lens optical property profile defining said central primary optical zone and said secondary zone with the additional dioptric power.

Images