"This study aimed to evaluate the equivalence of a smartphone-based visual acuity chart with a standard 6-m Snellen visual acuity (6SVA) chart." Researchers first reviewed Snellen chart apps that were ...
And now a page from our "Sunday Morning" Almanac, January 18th, 1908, 107 years ago today . . . the day the Dutch ophthalmologist Herman Snellen died at the age of 73. You may not recognize his name, ...