A vision screening apparatus includes first and second display units, a processor, and instructions which are executable by the processor. The instructions, when executed by the processor, cause the apparatus to 1) carry out a photorefraction test of a subject, 2) estimate the subject's visual acuity based on the photorefraction test, 3) present the subject with a visual acuity check optotype for an interval of time, and 4) monitor for noncompliance with a visual acuity check protocol during at least part of the time interval.

The present disclosure relates generally to systems and methods for determining the refractive error of a patient, more particularly determining the patient's refractive error by using a computerized screen, and providing a prescription for the patient's preferred type of corrective lenses. In a general embodiment, the present disclosure provides a method for determining a corrective lenses prescription of a patient. The method includes, separately, for each eye of the patient, determining an astigmatism prescription for the patient via a computerized screen and without the use of a refractor lens assembly, including instructing the patient to move a known, fixed distance away from a computerized screen and testing for a cylinder component by sequentially presenting at least two cylinder diagrams to the patient via the computerized screen and enabling the patient to select at least one input per cylinder diagram, where those inputs correspond to cylinder measurements for determining the prescription.

The present disclosure relates generally to systems and methods for determining the refractive error of a patient, more particularly determining the patient's refractive error by using a computerized screen, and providing a prescription for the patient's preferred type of corrective lenses. In a general embodiment, the present disclosure provides a method for determining a corrective lenses prescription of a patient. The method includes, separately, for each eye of the patient, determining an astigmatism prescription for the patient via a computerized screen and without the use of a refractor lens assembly, including instructing the patient to move a known, fixed distance away from a computerized screen and testing for a cylinder component by sequentially presenting at least two cylinder diagrams to the patient via the computerized screen and enabling the patient to select at least one input per cylinder diagram, where those inputs correspond to cylinder measurements for determining the prescription.

A method, a device, and a computer program product for determining a refractive error of an eye of a user are disclosed, as well as a method for producing a spectacle lens. The method for determining includes: a) displaying an image with a spatial modulation to the user; b) optionally, recording a reaction of the user to a variation of the spatial modulation over time; c) detecting a point in time at which a perception threshold of the user is reached; and d) determining the refractive error of the user from the spatial modulation, wherein the image contains a source image with several picture elements, wherein values for an image parameter are assigned to the picture elements, and wherein the spatial modulation is generated such that the values of the image parameter determine the values of a modulation parameter of the spatial modulation in the image.

A method, a device, and a computer program product for determining a refractive error of an eye of a user are disclosed, as well as a method for producing a spectacle lens. The method for determining includes: a) displaying an image with a spatial modulation to the user; b) optionally, recording a reaction of the user to a variation of the spatial modulation over time; c) detecting a point in time at which a perception threshold of the user is reached; and d) determining the refractive error of the user from the spatial modulation, wherein the image contains a source image with several picture elements, wherein values for an image parameter are assigned to the picture elements, and wherein the spatial modulation is generated such that the values of the image parameter determine the values of a modulation parameter of the spatial modulation in the image.

A booth, for using the Teller technique to quantify visual acuity, irrespective of a patient's verbal ability booth comprises a modular structure, making up an isolated environment for the patient to perform the acuity test through the reading of Teller cards. The patient is accommodated in a visualization area at the central portion of a movable wall sliding via wheels on rails installed on the ground and ceiling by profiles. The modular structure presents a white and opaque tone, as well as its own lighting which is controlled and proper according to the test, in front of a movable wall and coplanar to a rear wall of booth. The movable wall sliding effects the distance adjustment between the patient and the visualization area cards where the minimum distance is equivalent 38 centimeters and the maximum distance is 55 or 84 centimeters as accuracy dictates, according to the patient's features.

A booth, for using the Teller technique to quantify visual acuity, irrespective of a patient's verbal ability booth comprises a modular structure, making up an isolated environment for the patient to perform the acuity test through the reading of Teller cards. The patient is accommodated in a visualization area at the central portion of a movable wall sliding via wheels on rails installed on the ground and ceiling by profiles. The modular structure presents a white and opaque tone, as well as its own lighting which is controlled and proper according to the test, in front of a movable wall and coplanar to a rear wall of booth. The movable wall sliding effects the distance adjustment between the patient and the visualization area cards where the minimum distance is equivalent 38 centimeters and the maximum distance is 55 or 84 centimeters as accuracy dictates, according to the patient's features.

A method to self-test vision of a user for use with a handheld vision tester includes receiving image data of the user's face, determining dimensions of the user's face based on the received image data, computing a user viewing distance based on the determined dimensions, displaying a vision test based on the computed user viewing distance, receiving user input responses to the vision test, and outputting results of the vision test from the user input responses.

A method to self-test vision of a user for use with a handheld vision tester includes receiving image data of the user's face, determining dimensions of the user's face based on the received image data, computing a user viewing distance based on the determined dimensions, displaying a vision test based on the computed user viewing distance, receiving user input responses to the vision test, and outputting results of the vision test from the user input responses.

Disclosed is an apparatus for measuring subjective ocular refraction including a display device configured to display a least one optotype and a refractive optical system arranged between an eye of a viewer and the display device, the refractive optical system having an optical power that can be varied according to a determined minimum step. The display device further includes a unit for varying optical power designed to generate a variation in the spherical and/or cylindrical optical power, such that the display device and the refractive optical system form a first image of the optotype with a first total optical power and, respectively, a second image of the optotype with a second total optical power, the variation in optical power between the first total optical power and the second total optical power being less than the determined minimum step.