Visual acuity test The visual acuity test is used to determine
the smallest letters you can read on a standardized chart
(Snellen chart) or a card held 20 feet away. Special charts are
used when testing at distances shorter than 20 feet. Eye test -
acuity; Vision test - acuity; Snellen test How the test is
performed This test may be done in a health care provider's
office, a school, a workplace, or elsewhere. You will be asked
to remove your glasses or contact lenses and stand or sit 20
feet from the eye chart. You will keep both eyes open. You will
be asked to cover one eye with the palm of your hand, a piece of
paper, or a small paddle while you read out loud the smallest
line of letters you can see on the chart. Numbers or pictures
are used for people who cannot read, especially children. If you
are not sure of the letter, you may guess. This test is done on
each eye, one at a time. If needed, it is repeated while you
wear your glasses or contacts. You may also be asked to read
letters or numbers from a ca