A system is provided for determining a risk indicator for myopia. The system comprises a wearable device configured to be attached to a body of a user. The wearable device comprises at least one distance sensor configured to determine at least a first distance value indicative of a distance between the wearable device and an object located in a central vision zone of the user and a second distance value indicative of a distance between the wearable device and an object located in a peripheral vision zone of the user. The system further comprises a control unit configured to determine, based on the first distance value and the second distance value, a risk indicator for myopia. Further, a method and a computer program product are provided.

Disclosed herein are methods and systems of evaluating test-retest precision using fractional rank precision or mean-average precision, comprising: a) collecting a test and a retest result of each subject, wherein the results are described in feature space(s) and collected from a vision test machine; b) selecting, a first test result of a first subject; c) calculating distances from the first test result to the retest result of each subject; d) assessing, a similarity between the first test result and the retest result of each subject by ranking the distances in a non-descending order; e) assessing a rank precision for the first subject based on a rank of a distance from the first test result to the retest result of the first subject; f) repeating b), c), d), and e) for each subject; and evaluating, the test-retest precision based on the rank precision for each of the plurality of subjects.

Disclosed herein are methods and systems of evaluating test-retest precision using fractional rank precision or mean-average precision, comprising: a) collecting a test and a retest result of each subject, wherein the results are described in feature space(s) and collected from a vision test machine; b) selecting, a first test result of a first subject; c) calculating distances from the first test result to the retest result of each subject; d) assessing, a similarity between the first test result and the retest result of each subject by ranking the distances in a non-descending order; e) assessing a rank precision for the first subject based on a rank of a distance from the first test result to the retest result of the first subject; f) repeating b), c), d), and e) for each subject; and evaluating, the test-retest precision based on the rank precision for each of the plurality of subjects.

Systems and methods are provided for improving overall vision in patients suffering from a loss of vision in a portion of the retina (e.g., loss of central vision) by providing a piggyback lens which in combination with the cornea and an existing lens in the patient's eye redirects and/or focuses light incident on the eye at oblique angles onto a peripheral retinal location. The piggyback lens can include a redirection element (e.g., a prism, a diffractive element, or an optical component with a decentered GRIN profile) configured to direct incident light along a deflected optical axis and to focus an image at a location on the peripheral retina. Optical properties of the piggyback lens can be configured to improve or reduce peripheral errors at the location on the peripheral retina. One or more surfaces of the piggyback lens can be a toric surface, a higher order aspheric surface, an aspheric Zernike surface or a Biconic Zernike surface to reduce optical errors in an image produced at a peripheral retinal location by light incident at oblique angles.

Disclosed herein are methods and systems of evaluating test-retest precision using fractional rank precision or mean-average precision, comprising: a) collecting a test and a retest result of each subject, wherein the results are described in feature space(s) and collected from a vision test machine; b) selecting, a first test result of a first subject; c) calculating distances from the first test result to the retest result of each subject; d) assessing, a similarity between the first test result and the retest result of each subject by ranking the distances in a non-descending order; e) assessing a rank precision for the first subject based on a rank of a distance from the first test result to the retest result of the first subject; f) repeating b), c), d), and e) for each subject; and evaluating, the test-retest precision based on the rank precision for each of the plurality of subjects.

Disclosed herein are methods and systems of evaluating test-retest precision using fractional rank precision or mean-average precision, comprising: a) collecting a test and a retest result of each subject, wherein the results are described in feature space(s) and collected from a vision test machine; b) selecting, a first test result of a first subject; c) calculating distances from the first test result to the retest result of each subject; d) assessing, a similarity between the first test result and the retest result of each subject by ranking the distances in a non-descending order; e) assessing a rank precision for the first subject based on a rank of a distance from the first test result to the retest result of the first subject; f) repeating b), c), d), and e) for each subject; and evaluating, the test-retest precision based on the rank precision for each of the plurality of subjects.

A system, method, and non-transitory computer readable medium for providing a visual examination are provided. A diagnostic module configured to execute on a first computing device communicatively coupled to a head mounted holographic display device worn by a user renders a virtual arrangement displayed within the head mounted holographic display device at an initial simulated distance away from the user. Within the virtual arrangement is an imbedded pattern. A second computing device receives, from leads attached to the user, brain waves of the user. The second computing device displays a visual evoked potential within the brain waves. The visual evoked potential comprises an indication that the user visually identified the imbedded pattern at a second simulated distance away from the user. The visual evoked potential occurs at a focal length of a refractive error of an eye of the user.

Disclosed embodiments may include a device, system and method for providing a low cost device that can measure refractive errors very accurately via attachment to a smart phone. A disclosed device may use ambient light or a light source in simulating the cross cylinder procedure that optometrists use by utilizing the inverse Shack-Hartman technique. Using an optical device, in conjunction with a smart phone, the user first changes the angle of the axis until he/she sees a cross pattern (the vertical and horizontal lines are equally spaced). The user adjusts the display, using motorized controls on the on the optical device, to make the lines come together and overlap, which corresponds to bringing the view into sharp focus, thus determining the appropriate optical prescription for the user.

Disclosed embodiments may include a device, system and method for providing a low cost device that can measure refractive errors very accurately via attachment to a smart phone. A disclosed device may use ambient light or a light source in simulating the cross cylinder procedure that optometrists use by utilizing the inverse Shack-Hartman technique. Using an optical device, in conjunction with a smart phone, the user first changes the angle of the axis until he/she sees a cross pattern (the vertical and horizontal lines are equally spaced). The user adjusts the display, using motorized controls on the on the optical device, to make the lines come together and overlap, which corresponds to bringing the view into sharp focus, thus determining the appropriate optical prescription for the user.

Consumer products such as refraction measurement devices may be used for obtaining refraction measurements allow consumers to track their vision without visiting an optometrist or ophthalmologist. Such consumer products may work in concert with smart phones or other products having a touch screen that present images to refraction measurement devices. Smart phones may have resolution rates, sometimes measured as PPI or pixels per inch that are unknown to the user and/or refraction measurement device. One aspect of the invention is to provide an optical interface for the user to manually match the view port boundary of the smartphone to comport with the view port boundary of the refraction measurement device. Another aspect of the invention is the use of pre-distortion in images presented to the user. By noting the corrective movements exerted by the user upon the refractive measurement device, the user's own refractive error can be derived.