What is Visual Acuity

Visual Acuity

Visual acuity is the sharpness or clearness of vision. It is the ability of
the eyes to see fine detail and is determined by how effectively light is
focused in each eye.

Testing distance visual acuity is a common measure of eyesight. It
involves reading the letters on an eye chart across the room. A reduced
eye chart can also be used to measure near visual acuity at normal
reading distances.

The level of visual acuity is written as a fraction such as 20/40. The top
number in the fraction is the standard distance at which testing is done,
twenty feet. The bottom number is the smallest letter size the child was
able to read.

Normal distance visual acuity is 20/20. A child with 20/40 visual acuity
would have to get within 20 feet of a letter that should be seen as far
away as 40 feet in order to see it clearly.

If a child has less than "normal" or 20/20 visual acuity, he or she may
have difficulty copying from the chalkboard or watching a movie in
class. Unfortunately, this is often the only visual ability tested during a
school vision screening. While it is important, having 20/20 visual
acuity does not mean a person has "perfect" vision.

Other vision skills such as eye focusing, eye teaming and eye tracking
are needed in the classroom and on the playground. So even if you child
passes a vision screening or eye test with 20/20 visual acuity, don't
assume he or she doesn't have a vision problem.