Abstract: An alignment device including means for releasably attaching a suction ring and means for applying a pattern of light to an eye of a patient. The alignment device further including means for detecting light reflected from the eye and determining whether the suction ring is aligned relative to the eye based on the detected light.

Abstract: To promptly take a high quality image of an object to be inspected, provided is an imaging method for taking an image of the object to be inspected by irradiating the object to be inspected with measuring light, in which an aberration generated in the object to be inspected is corrected by an aberration correction unit. The method includes the repeatedly performed steps of measuring the aberration generated in the object to be inspected, correcting the aberration by controlling the aberration correction unit in accordance with the measured aberration, and storing, in a storage unit, a control state of the aberration correction unit in association with the measured aberration. The aberration correction unit is controlled in a predetermined control state stored in the storage unit.

Abstract: An image processing apparatus acquires a tomographic image of an eye to be examined. The image processing apparatus quantifies a distortion in a region determined from the tomographic image. The region includes a photoreceptor layer or a retinal pigment epithelium.

Abstract: An ophthalmic endoillumination system comprises a self-contained power source and a laser light source powered by the self-contained power source to produce light. The system further comprises an elongated member sized for insertion into an eye and for conducting the light produced by the laser light source.

Abstract: A method for Determining at Least One Parameter for Diagnosis or Risk Assessment of a Disease, including AMD. The distribution of the macular pigment MP of an eye and at least one area A whose bordering line corresponds to a constant optical density MPD and/or concentration MPC of MP is determined by an analysis unit. The bordering line is subjected to a quantitative shape description. At least one parameter DP, suitable for diagnosing a disease and/or the risk of a disease is derived from the quantitative shape description of the bordering line of the areas A. The method is provided for diagnosis or risk assessment but may also be used in the context of treatment of macular pigment deficiency phenomena to select the required supplements. This method, based on the determination of the fractal dimension, is also suitable for diagnosing other diseases such as edemas, actinomycoses, atrophies or lesions.

Abstract: A mask is provided that is configured to increase the depth of focus of a patient. The mask can include an aperture configured to transmit along an optical axis substantially all visible incident light. The mask can further include a portion surrounding at least a portion of the aperture. The portion may be configured to be substantially opaque to visible electromagnetic radiation and be substantially transparent to electromagnetic radiation transmitted from an ocular examination device (e.g., substantially transparent to at least some non-visible electromagnetic radiation with a wavelength between about 750 nm and about 1500 nm).

Abstract: There is provided a system, apparatus and methods for developing laser systems that can create a precise predetermined capsulotomy. The systems, apparatus and methods further provide laser systems that reduce the patient-to-patient variability and doctor-to-doctor variability associated with hand held apparatus for performing capsulorhexis and capsulotomies. There is further provided a precise predetermined shot pattern and shaped capsulotomy that is based at least in part on the shape of an IOL and in particular an accommodating IOL.

Abstract: The invention relates to an ophthalmological analysis method for measuring an intraocular pressure in an eye with an analysis system consisting of an actuating device with which a cornea of the eye is deformed in contactless manner, wherein the actuating device causes a puff of air to be applied to the eye in such manner that the cornea is deformed, an observation system with which the deformation of the cornea is observed and recorded, wherein sectional images of the cornea when it is deformed and not deformed are created with the observation device, and an analysis device with which the intraocular pressure is derived from the sectional images of the cornea, wherein a material characteristic of the cornea is derived from the sectional images of the cornea in the analysis device, wherein a stiffness of the cornea is derived as a material characteristic.

Abstract: A macular region visual defect index calculation apparatus including: visual field probe screen generating means; fixation image displaying and controlling means; probe region setting means; probe points setting means; visual target displaying and controlling means; first counting means; second detection means; second counting means; and visual defect index calculation means for dividing the number of times counted and stored on a memory device by the second counting means, by the total number counted and stored on a memory device by the first counting means; wherein the probe region being locally set mainly in macular region. So, according to the present invention of a macular region visual defect index calculation apparatus, a ratio of visual defect region to macular region can be calculated as an index, and the degree of visual defect against macular region can be numerically grasped.

Abstract: The invention relates to an opthalmological analysis method for measuring an intraocular pressure in an eye with an analysis system consisting of an actuating device, wherein the actuating device causes a puff of air to be applied to the eye in such manner that the cornea is deformed, an observation system with which the deformation of the cornea is observed and recorded, wherein sectional images of the cornea when it is deformed and not deformed are created with the observation device, and an analysis device with which the intraocular pressure is derived from the sectional images of the cornea, wherein a material characteristic of the cornea is derived from the sectional images of the cornea in the analysis device, wherein a diameter d1 of a first applanation area of the cornea and a diameter dn of a deformation area of the cornea is derived as a material characteristic.

Abstract: A method of making a shelter spectacle for existing spectacles through a public network, includes the steps of gathering dimensional information on the existing spectacles worn by a user; sending the dimensional information on the existing spectacles to a fulfillment center through the public network; according to the dimensional information sent by the user, producing a shelter spectacles which fit the existing spectacles worn by the user; and sending the shelter spectacles back to the user.

Abstract: Wavefront measurements of eyes are often taken when the pupil is in a first configuration in an evaluation context. The results can be represented by a set of basis function coefficients. Prescriptive treatments are often applied in a treatment context, which is different from the evaluation context. Hence, the patient pupil can be in a different, second configuration, during treatment. Systems and methods are provided for determining a transformed set of basis function coefficients, based on a difference between the first and second configurations, which can be used to establish the vision treatment.

Abstract: A blink detection algorithm and associated circuitry for an ophthalmic lens comprising an electronic system is described herein. The blink detection algorithm is implemented in the system controller which is part of an electronic system incorporated into the ophthalmic lens. The electronic system includes one or more batteries or other power sources, power management circuitry, one or more sensors, clock generation circuitry, control algorithms and circuitry, and lens driver circuitry.

Abstract: An image processing apparatus includes an obtaining unit configured to obtain a tomographic image including an optic disc portion and a macula portion of a fundus of a subject's eye, an analysis unit configured to analyze the optic disc portion and the macula portion of the fundus in the tomographic image, and a display control unit configured to display side-by-side, on a display unit, a display pattern indicating a result of analyzing the optic disc portion, and a display pattern indicating a result of analyzing the macula portion.

Abstract: An optical coherence tomography imaging apparatus that captures a tomographic image of a subject's eye using interference light based on light from a wavelength-swept light source includes a region acquisition unit configured to acquire an imaging target region, a display control unit configured to display information about the acquired imaging target region, and an imaging unit configured to capture a tomographic image by scanning the imaging target region in the subject's eye using light from the wavelength-swept light source.

Abstract: To determine an opening degree of a chamber angle with higher accuracy compared to that of a conventional technology, provided is an anterior ocular segment tomographic image analysis method including: a first determination step of determining an approximated line that approximates a shape of an anterior surface of an iris along the anterior surface of the iris in an anterior ocular segment tomographic image; a second determination step of determining an approximated line extended part obtained by extending the approximated line until the approximated line crosses a baseline in contact with an inner surface of a cornea and an inner surface of a sclera of an anterior ocular segment in the anterior ocular segment tomographic image; and a calculation step of calculating an opening degree of an anterior chamber angle of the anterior ocular segment through use of the approximated line and the approximated line extended part.

Abstract: Ocular surface interferometry (OSI) devices, systems, and methods are disclosed for measuring a tear film layer thickness (TFLT) of the ocular tear film, including lipid layer thickness (LLT) and/or aqueous layer thickness (ALT). The measured TFLT can be used to diagnosis dry eye syndrome (DES). In certain disclosed embodiments, a multi-wavelength light source can be controlled to illuminate the ocular tear film. Light emitted from the multi-wavelength light source undergoes optical wave interference interactions in the tear film. An imaging device can be focused on the lipid layer of the tear film to capture optical wave interference interactions of specularly reflected light from the tear film combined with a background signal(s) in a first image. The imaging device can also be focused on the lipid layer of the tear film to capture a second image containing the background signal(s) present in the first image.

Abstract: Methods and systems for obtaining an ocular aberration measurement of an eye of a patient are provided. Exemplary techniques involve obtaining a first induced metric for the eye that corresponds to a first accommodation state of the eye, obtaining a second induced metric for the eye that corresponds to a second accommodation state of the eye, and determining a natural metric of the eye based on the first and second induced metrics. An induced metric may include a pupil size or a spherical aberration. Techniques can also include determining a target metric for the eye base on the natural metric, determining whether an actual metric of the eye meets the target metric, obtaining an ocular aberration measurement of the eye if the actual metric meets the target metric, and determining a treatment for the eye based on the ocular aberration measurement.

Abstract: An ophthalmic apparatus for measuring spatial distances within a patient's eye is disclosed. The apparatus can be used to measure, for example, the capsular bag depth in an aphakic eye. The spatial measurement system can direct laser light into a patient's eye so that a portion of the light is scattered by the capsular bag. The scattered light can be directed to a detector where spots can be formed corresponding to the locations on the capsular bag from which the light was scattered. The distance from the cornea to the capsular bag can be determined based, for example, at least in part on the distance between the spots formed on the detector. In some embodiments, the apparatus can include a surgical microscope and/or a wavefront aberrometer. In some embodiments, an alignment system can be used to precisely position the apparatus relative to the patient's eye.

Abstract: The invention utilizes a digital holographic adaptive optics (DHAO) system to replace hardware components in a conventional AO system with numerical processing for wavefront measurement and compensation of aberration by the principles of digital holography. Wavefront sensing and correction by DHAO have almost the full resolution of a CCD camera. The approach is inherently faster than conventional AO because it does not involve feedback and iteration, and the dynamic range of deformation measurement is essentially unlimited. The new aberration correction system can be incorporated into a conventional fundus camera with minor modification and achieve high resolution imaging of a retinal cone mosaic. It can generate profiles of the retinal vasculature and measure blood flow. It can also provide real-time profiles of ocular aberration during refractive (Lasik) surgery and generate three-dimensional maps of intraocular debris.

Abstract: Tomographic images of a plurality of planes at a disease site of a fundus are taken exactly within a short period of time, and the tomographic images are respectively displayed so that the positional relationship thereof becomes clear. A low coherent optical tomographic image sensing apparatus for imaging a fundus includes a sensing unit which takes tomographic images of a plurality of planes intersecting each other in time division, a display unit which displays the taken tomographic images at separate sites on the identical screen, and a position indication unit which displays, in each tomographic image, an intersection position of the tomographic image and another tomographic image intersecting one another.

Abstract: An apparatus and method of providing an ophthalmic image is presented. In accordance with embodiments of the present invention, an illumination path with a focus index optical assembly and a first diopter compensator is provided and an imaging path with a sensor and a second diopter compensator is provided. The first diopter compensator and the second diopter compensator can be adjusted to provide focus according to a focus index from the focus index optical assembly.

Abstract: Methods of estimating the size of an ocular lens capsule.

Abstract: The present invention relates to means for creating a visual illusion of directional movement. In various embodiments, methods for using the directional illusion are provided, such as, for the measurement and/or assessment of visual performance and/or acuity, for evaluating visual performance in various settings, enhancing advertising and marketing by drawing attention to a desired symbol, or enhancing images.

Abstract: A method and system for simulating/emulating vision using intraocular devices or lenses prior to surgery, preferably using multifocal and monofocal intraocular lenses. The invention allows the patient, prior to surgery, to compare the differences in the perception of an image as seen with the intraocular lens and with normal vision, determining which type of lens the patient prefers, and in turn allows the ophthalmologist to measure which provides the better visual performance. The invention comprises a system containing the intraocular lens, called an artificial eye, a lens for transporting the image from the intraocular lens and eliminating the blur introduced by the artificial eye, and at least one telescope or optometer which transports the intermediate image from the intraocular lens onto the patient's pupil. In this manner, the patient is shown how he/she would see after surgery with each type of lens proposed by the ophthalmologist.

Abstract: The invention relates to devices and methods for selecting IOLs for implantation and eye models useful with the methods. One method comprises the steps of determining the axial eye length, the pupil size at a desired light level; the desired postoperative refraction; determining an aspheric representation of the corneal curvature and determining the location of the plane of fixation of the IOL following implantation.

Abstract: A sensor system includes at least two sensors for distinguishing accommodative stimuli from changes in ambient lights levels and task-induced changes in the pupil diameter. When implanted, the first sensor is disposed completely within the pupil; even when fully constricted, the pupil does not occlude the first sensor, allowing the sensor to make precise measurements of ambient luminous flux levels. The pupil occludes part of the second sensor's active area(s) as the pupil dilates and constricts. As a result, the second sensor measures both ambient luminous flux and pupil diameter. A processor estimates the pupil diameter and determines whether it's changing in response to accommodative stimuli or other factors by comparing to predetermined values. The sensor system sends a signal to an optical component, which in turn can respond by changing optical power to focus for near vision upon detection of accommodative stimuli.

Abstract: The eye is illuminated by a variable laser light source with a measurement range corresponding to the eye length, wherein the focus of the laser beam in the eye can be shifted laterally and/or axially by an adjustment mechanism, and the light fractions back-scattered from the sample are captured via an interferometer by a data acquisition unit and forwarded to a data processing unit. In the data processing unit, an OCT whole-eye scan is combined with at least one or several further overlapping tomographic part-eye or whole-eye scans. Reference information is used to register the first whole-eye scan with the further part-eye or whole-eye scans, and the combined whole-eye scan is evaluated and/or displayed on a user surface.

Abstract: Wavefront measurements of eyes are typically taken when the pupil is in a first configuration in an evaluation context. The results can be represented by a set of basis function coefficients. Prescriptive treatments are often applied in a treatment context, which is different from the evaluation context. Hence, the patient pupil can be in a different, second configuration, during treatment. Systems and methods are provided for determining a transformed set of basis function coefficients, based on a difference between the first and second configurations, which can be used to establish the vision treatment.

Abstract: Systems for imaging structures of a subject are provided. The subject has an optical axis, a pupil, and a nodal point. The system includes an image capture device; a first structure including a mount for the subject to be imaged by the image capture device, the first structure providing at least two rotational degrees of freedom; a second structure including a mount for the image capture device, the second structure providing at least two translational degrees of freedom; and a means for aligning the image capture device in relation to the optical axis, the pupil, and the nodal point of the subject.

Abstract: A device for performing distance measurements on an eye. The device includes an interferometer, focuses at least one measurement beam records backscattered radiation and interferometrically generates a measurement signal displaying structures of the eye by time-domain, spectral-domain or Fourier-domain coherence reflectometry, has an adjustment apparatus for laterally and/or axially displacing the focus in the eye or for varying a polarization state of the measurement beam and has a control apparatus which actuates the interferometer, wherein the control apparatus generates a plurality of A-scan individual signals from the backscattered radiation, combines these to an A-scan measurement signal and actuates the adjustment apparatus for displacing the position of the focus or for varying the polarization while recording the backscattered radiation from which the control apparatus generates the A-scan individual signals is being recorded.

Abstract: A Pupillometer is disclosed. The Pupillometer has a display, an imaging apparatus that has a pupil finder and a microprocessor, and a memory in communication with the microprocessor. The display is sized to simultaneously display a video of y or more seconds in length of a left pupil and a video of y or more seconds in length of a right pupil. The pupil finder identifies the perimeter of a pupil. The imaging apparatus is capable of recording images of an individual's pupils at a rate of x image frames per second for a period of y or more seconds and playing back said image frames as a video at x image frames per second or at another rate that is faster or slower than x image frames per second.

Abstract: A method of testing visual performance includes determining a difficulty rating for each of a plurality of visual recognition tests. The method further includes displaying one of the visual recognition tests to a subject and receiving from the subject a response to the visual recognition test. After receiving the response to the visual recognition test, a subsequent visual recognition test is selected to have a difficulty rating determined based on the response received from the subject, the subsequent visual recognition test is displayed, and a response is received from the subject. The subsequent visual recognition tests are repeated until a predetermined number of responses is reached. A visual performance score is determined based on the set of responses received from the subject and the difficulty ratings for the visual recognition tests displayed to the subject is then output.

Abstract: A methodology is provided for correcting the placement of a laser beam's focal point. Specifically, this correction is done to compensate for displacements of the focal point that may be caused when implant material (e.g. an Intraocular Lens (IOL)) is positioned on the optical path of the laser beam. The methodology of the present invention then determines a deviation of the laser beam's refracted target position (uncompensated) from its intended target position. A calculation of the deviation includes considerations of the laser beam's wavelength and refractive/diffractive characteristics introduced by the implant material. This deviation is then added to the refracted target position to make the refracted target position coincide with the intended target position of the focal point. The laser beam will then focus to its intended target position.

Abstract: In an image processing apparatus that irradiates an object to be inspected with measuring light and synthesizing a plurality of tomographic images acquired on the basis of reflected light to form a new tomographic image in order to reduce speckles in the image and enhance the image quality of the resultant composed image in imaging using optical coherence tomography, the image processing apparatus is provided with an image acquiring unit that acquires a plurality of tomographic images of an object to be inspected and a selection unit that selects tomographic images to be composed from among the plurality of tomographic images on the basis of similarity information about the plurality of tomographic images.

Abstract: A system and method are provided that use eye gaze as a pointing or selection tool, which enables hands-free operation of a display such as a television. wherein the use of eye gaze as an input can also lead to easier and faster interactions when compared to traditional remote controls. A system and method are also provided that use eye tracking on displays such as televisions to determine what content was viewed and, by association, what content was of most interest to the user. Systems and methods are also described that enable interaction with elements displayed in an augmented reality environment using gaze tracking and for controlling gaze tracking on a portable electronic device.

Abstract: Systems and methods for documenting, recording, and interpreting the eccentric photorefraction, pupillary light reflex and the corneal light reflex eye screening tests in infants and young children. The system includes a computing device having an image capturing device, a light generating device, and a display. The system includes a computer application that is executable on the computing device and operative to utilize the computing device to perform eye screening tests. The system also includes a website that allows users to upload captured images from the computing device, so that the images may be processed, analyzed, and recorded.

Abstract: In order to detect a deterioration status of an imaging light source in an accurate manner, an ophthalmologic apparatus includes a light intensity detection unit configured to detect a light intensity of light emitted from the imaging light source, a determination unit configured to determine a status of the imaging light source on the basis of the light intensity detected by the light intensity detection unit and a light emitting time of the imaging light source, and a display control unit configured to display, on a display unit, the status of the imaging light source on the basis of a determination result by the determination unit.

Abstract: Provided is a fundus imaging apparatus which achieves reduction of a load on an examiner by facilitating understanding of an operation of switching from a fundus imaging mode to an anterior ocular segment imaging mode, comprising: an imaging unit for taking an image of an eye to be inspected; a focusing unit for achieving a substantially conjugate relationship between the eye to be inspected and the imaging unit; a diopter adjustment unit for adjusting a diopter when the eye to be inspected is myopic or hyperopic; an imaging selecting unit capable of selecting the fundus imaging mode or the anterior ocular segment imaging mode; a diopter adjustment switching unit for switching the diopter adjustment unit in accordance with the selected imaging mode; and a drive unit for driving the focusing unit in accordance with the selected imaging mode.

Abstract: An eye refractive power measurement apparatus includes a measurement optical system, a calculator and an output unit. The measurement optical system projects measurement light onto a fundus of an examinee's eye, extracts the measurement light reflected on the fundus as ring-shaped light, and causes an imaging device to capture a ring-shaped image. The calculator measures eye refractive power of the examinee's eye, based on the ring-shaped image captured by the imaging device, specifies a position of the ring-shaped image to calculate a measured line of the image, performs approximate processing on the measured line to calculate an approximate curve, and calculates a displacement between the measured line and the approximate curve in a meridian direction for each divided region. The output unit outputs a measurement result of the eye refractive power and a calculation result of the displacement in each divided region.

Abstract: Systems and methods related to corneal ablation for treatment of one or more high-order optical aberrations are provided. A method includes providing a defect-correcting prescription, determining an ablation profile to impose the prescription on the cornea, and determining a sequence of laser-energy ablations to impose the ablation profile on the cornea. The prescription comprises a high-order optical correction. The ablation profile includes a first-segment profile and a second-segment profile. The second-segment profile corresponds to at least one high-order optical correction. The ablation sequence includes applying ablations corresponding to the first-segment profile prior to applying ablations corresponding to the second-segment profile.

Abstract: Systems for extended depth frequency domain optical coherence tomography are provided including a detection system configured to sample spectral elements at substantially equal frequency intervals, wherein a spectral width associated with the sampled spectral elements is not greater than one-half of the frequency interval. Related methods are also provided herein.

Abstract: A method for generating a radial alignment guide for an eye includes collecting preoperative corneal topography data. The data includes a corneal vertex location and a pupil center location for an eye that is not dilated. The method then includes locating a dilated pupil center for the eye after the eye is dilated. The method further includes determining an adjusted offset between the corneal vertex and the dilated pupil center and displaying alignment data on an image of the eye based on the adjusted offset.

Abstract: A retinal imaging device includes an optical system configured to (i) scan a portion of the retina of the eye with a line of light, (ii) descan reflected light from the scanned portion of the retina, and (iii) provide output light in a line focus configuration. The device includes a detection device including a linear array of asymmetric pixels having at least a 2:1 ratio of length to width, a detection device with multiple adjacent linear arrays, and/or a detection device using a time delay and integration (TDI) architecture.

Abstract: The present patent application discloses a digital slit-lamp microscope system and the methods of the electronic recording and remote diagnosis. The present patent application relates to the field of optical instrument and remote communication control. The purpose is to solve the problems of the electronic recording, reappearing and remote diagnosis of the slit-lamp image. The digital slit-lamp microscope system comprises digital slit-lamp microscope side, communication unit and client side. The digital slit-lamp microscope side includes a build-in slit-lamp microscope and is connected to the communication unit and the client side in sequence. The digital slit-lamp microscope side irradiates the eyes of the patient, and then transmits the pathology information of the eyes of the patient to the communication unit and the client side in sequence.

Abstract: Background reduction apparatuses and methods of Ocular surface interferometry (OSI) employing polarization are disclosed for measuring a tear film layer thickness (TFLT) of the ocular tear film, including lipid layer thickness (LLT) and/or aqueous layer thickness (ALT) and can be used to evaluate and potentially diagnosis dry eye syndrome (DES). In certain disclosed embodiments, a multi-wavelength light source can be controlled to illuminate the ocular tear film. Light emitted from the multi-wavelength light source undergoes optical wave interference interactions in the tear film. An imaging device can be focused on the lipid layer of the tear film to capture optical wave interference interactions of specularly reflected light from the tear film combined with a background signal(s) in at least one image. The at least one image can be processed and analyzed to measure a tear film layer thickness (TFLT), including lipid layer thickness (LLT) and/or aqueous layer thickness (ALT).

Abstract: An ophthalmologic photographing apparatus includes: a photographing optical system that includes a scanning unit for scanning an examinee's eye with measurement light to obtain a tomographic image of the examinee's eye; an observing optical system that includes a light-receiving device for receiving reflected light from the examinee's eye to obtain a moving image of a front image of the examinee's eye based on a light-receiving signal from the light-receiving device; a display controller for displaying the front image acquired by the observing optical system in a still state on a monitor as well as enabling setting of a capturing position of the tomographic image, the setting using the front image; and a drive controller for controlling the scanning unit to acquire the tomographic image in accordance with the capturing position.

Abstract: The invention relates to a method for measuring the curve of a spectacle frame (4) comprising the following operations: determining the position of a first reference mark (18) defining the mid plane of the spectacle frame (4); determining the position of a second reference mark (20) defining the orientation of a spectacle lens holder relative to said mid plane; and measuring the angle between said first and second reference marks. The invention also relates to a device for carrying out the method.

Abstract: An eye chart uses a series of graphics spaced at intervals selected to discriminate between normal vision and vision impaired by the presence of a cataract and displayed on a digital display device such as a computer, digital display device, smart phone, etc. Groups of graphics have progressively different distances between the series with one series representing normal vision with the space between the lines growing progressively further apart to indicate the advancement of the cataract. A user with normal vision will be able to count the number of lines, while a person with cataracts will require the space between the lines to be further apart. The digital device automatically stores input information using an input device such as a mouse or touch screen input. This digital storage information records a patient profile in time as each use is recorded. Different shapes and letters may be used.

Abstract: A vision testing system comprises a image wavefront modulator, eye tracking system, focusing system using a spherical concave mirror, and a patient station. In various embodiments, the image wavefront modulator and the patient's eyes are positioned off axis with respect to the optical axis of the focusing mirror. Thus, optical elements in the wavefront modulator may automatically adjust to correct for aberrations introduced by the focusing system. Moreover, the optical elements may also be used to automatically correct for magnification errors introduced by movement of the patient within the patient testing station. Furthermore, the eye tracking system may be used to determine the errors introduced by movement of the patient eyes. Finally, the wavefront modulator may be used to produce an image on the patient's retina that accurately emulates an image that result if the patient was looking through a spectacle lens of a particular design during various gaze angles.