Impaired vision and blindness are common. About 3.4 million people in the US are blind or visually impaired. Vision is usually measured by visual acuity charts, and normal vision is expressed as 20/20 ...

Results from smartphone-based Snellen charts, which are eye charts used to measure visual acuity, are not consistent with results from standard Snellen visual acuity chart tests, according to a study ...

The Jaeger chart was designed to test near vision acuity. Eduard Jaeger von Jaxtthal (1818–1884) was an Austrian ophthalmologist and a professor at the University of Vienna who, in the 1850s, made ...