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Then, a reference scaling measurement is employed to calculate distance from the sensor to a user. To determine accuracy and generalizability, testing was conducted both with 200 static images, 25 images each of males and females for four ethnic groups from a facial image database, and live image streams from a test subject. Average absolute corneal radius error over 10 trials for the static images was 6.36%, while average absolute distance error for the live image streams was less than 1%. Subsequently, distance measurements were used to scale letter sizes for a Snellen Chart-based visual acuity assessment. This system enables monitoring of chronic retinal diseases, as patients can quickly and accurately measure their visual acuity through the mobile eye exam suite.<\/jats:p>","DOI":"10.1177\/1460458220958537","type":"journal-article","created":{"date-parts":[[2020,9,30]],"date-time":"2020-09-30T05:09:53Z","timestamp":1601442593000},"page":"3037-3055","update-policy":"https:\/\/doi.org\/10.1177\/sage-journals-update-policy","source":"Crossref","is-referenced-by-count":0,"title":["A mobile vision testing application based on dynamic distance determination from the human corneal limbus"],"prefix":"10.1177","volume":"26","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-4992-1356","authenticated-orcid":false,"given":"Neal A","family":"Patel","sequence":"first","affiliation":[{"name":"Stanford University, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Perry N","family":"Alagappan","sequence":"additional","affiliation":[{"name":"Stanford University, 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