As The Verge explains in the video below, eye charts measure one aspect of healthy vision: ... A perfect 20/20 score on an eye chart test doesn't mean you have perfect vision: Visual acuity, ...

The acuity measurement is done 20 feet away from the chart and the test is done with each eye separately. Most digital or electronic eye charts are based on a similar principle.

At least once in your life, you must have squinted at the eye chart at the doctor’s office or DMV, trying to make out the blurry bottom line. Turns out, there’s some very precise math that ...

In his famous eye chart, each row represents a different dioptre, which measures the distance you would have to be from the text to read it. Monoyer also inserted his name into the chart.

Eye doctor Herman Snellen (Dutch, 1834–1908) developed the most commonly used eye chart in the 1860s. The now iconic Snellen chart contains 11 rows of capital letters decreasing in size as the eye ...

As they described in a study, published in the Canadian Journal of Ophthalmology in February, the modern version of the Snellen chart consists of 11 lines of letters, printed in decreasing size ...

Eye - Performance of a computerised visual acuity measurement device in subjects with age-related macular degeneration: comparison with gold standard ETDRS chart measurements Skip to main content ...