What is 20/20 Vision?

Eyeglasses or contacts help you have 20/20 vision. But what does that really mean?

A person with 20/20 vision can see what an average individual can see on an eye chart when they are standing 20 feet away.

An eye chart measures visual acuity, which is the clearness or sharpness of vision. The top number is your distance in feet from the chart. The bottom number is the distance at which a person with normal eyesight can read the same line. For example, if you have 20/30 vision, it means your vision is worse than average. Twenty feet away, you can read letters most people see from 30 feet.

20/20 vision is not perfect vision. A person can have 20/15 vision, which is sharper than average. If you have 20/15 vision, you can see a line in the eye chart at 20 feet that the average person can only see when they are 15 feet away. The goal of glasses or contacts is to bring a person’s vision to 20/20.

Only about 35% of all adults have 20/20 vision without glasses, contact lenses or eye surgery. With correction, about 75% of adults have 20/20 vision. In most states, you need 20/40 vision or better for an unrestricted driver’s license. People are “legally blind” if their vision with glasses or contacts is 20/200 or worse.

Additionally, the term "20/20" denotes a person with excellent central vision. However, they may have other types of vision, such as side vision, night vision or color vision, that might be imperfect. Some potentially blinding eye diseases, such as glaucoma or diabetic retinopathy, can take years to develop. During this time, they are harming parts of the inner eye, but the central vision can remain unaffected.

Call 321-805-3700 to schedule your eye exam in Melbourne, Merritt Island, Palm Bay, Titusville or Rockledge.