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Visual acuity is a measure of how well a person can focus on an object. To test visual acuity, the person may read letters or symbols
on a chart 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.
For example, a person who can read what people
with normal vision can read at
20 ft (6 m) has 20/20 (6/6)
distance vision. The larger the second number, the worse the vision.
Current as of:
September 9, 2014
Kathleen Romito, MD - Family Medicine & Christopher J. Rudnisky, MD, MPH, FRCSC - Ophthalmology
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