Photorefraction ocular screening device and methods

摘要

A photorefraction ocular screening device for assessing vision and corresponding disorders associated with the human ocular system is provided. More specifically, the present invention provides for a photorefraction ocular screening device employing advanced methods of pupil detection and refractive error analysis. The photorefraction ocular screening device is comprised of an LED arrangement configured with a plurality of irradiation sources serving as visual stimuli, wherein the visual stimuli may be presented in varying illumination patterns to the pupils of an examinee for expanding the range of ocular responses that can be used to determine refractive error.

主权项

1. A computer-implemented method of determining refractive error, said method comprising the steps of:
receiving a first image and a second image corresponding to an axis-conjugate meridian; removing corneal glints present in pupil regions of said first image and said second image; applying a low-pass filter to each of said pupil regions; rotating said first image and said second image, after applying said low-pass filter to said pupil regions in each of said images, to align a stimulus angle in said axis-conjugate meridian associated with said first image and a stimulus angle in said axis-conjugate meridian associated with said second image with a horizontal meridian; extracting a pixel strip of data from each of said pupil regions centered on a pupil center in said first image and in said second image; computing a ratio of pixel intensity values using said pixel strips of data extracted from said first image and from said second image; generating a refractive error correlate measure based on said ratio of pixel intensity values; and converting said refractive error correlate measure to identify said refractive error.