Visual acuity is a measure of how well a person can focus on a
distant object. To test visual acuity, the person may read letters or symbols
on a wall chart (Snellen test) from the top down, line by line, covering first
one eye and then the other.
A visual acuity score is a ratio comparing the person's performance
to that of people who have "normal" vision. A person who can read what people
with normal vision can read at
20 ft (6 m) has 20/20 (6/6)
vision. The larger the second number, the worse the vision.
June 24, 2011
Kathleen Romito, MD - Family Medicine & Christopher J. Rudnisky, MD, MPH, FRCSC - Ophthalmology
To learn more visit Healthwise.org
© 1995-2012 Healthwise, Incorporated. Healthwise, Healthwise for every health decision, and the Healthwise logo are trademarks of Healthwise, Incorporated.