What does 20/20 vision mean? When you visit your doctor or an eye care professional, you may be asked to read an eye chart. You may be told you have normal 20/20 vision. What does that really mean? An ...

What is the farthest a human can see? What is the best recorded visual acuity? How far is the horizon? I am often asked these questions by clinicians and non-ophthalmologists and thought many of you ...

With more than 150 million people in the United States (nearly half of the population) requiring some form of corrective eyewear to compensate for visual impairment, chances are you have had your ...

Smartphone-based Snellen visual acuity charts has become popularized; however, their accuracy has not been established. This study aimed to evaluate the equivalence of a smartphone-based visual acuity ...

The right eyes of 35 healthy subjects were fogged with plus lenses and tested with the Snellen visual acuity chart (Reichert 11180). Visual acuity and counting level were assessed under various ...

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 ...

One would think that having normal 20/20 vision is due mainly to the anatomical characteristics of the eye. According to a new study, however, tiny eye movements play a large role – and the findings ...