Visual Acuity

Visual Acuity is the clarity or sharpness of vision.
Visual Accuity

Visual Acuity: What is 20/20 vision?

20/20 vision is a term used to express normal visual acuity (the clarity or sharpness of vision) measured at a distance of 20 feet. If you have 20/20 vision, you can see clearly at 20 feet what should normally be seen at that distance. If you have 20/100 vision, it means that you must be as close as 20 feet to see what a person with normal vision can see at 100 feet.

Having 20/20 vision does not necessarily mean you have perfect vision. 20/20 vision only indicates the sharpness or clarity of vision at a distance. Other important vision skills, including peripheral awareness or side vision, eye coordination, depth perception, focusing ability and color vision, contribute to your overall visual ability.

Some people can see well at a distance but are unable to bring nearer objects into focus. This condition can be caused by hyperopia (farsightedness) or presbyopia (loss of focusing ability). Others can see items that are close but cannot see those far away. This condition may be caused by myopia (nearsightedness).

A comprehensive eye examination by a doctor of optometry can diagnose what is affecting your ability to see well. In most cases, your doctor of optometry can prescribe glasses, contact lenses or a vision therapy program that will help improve your vision. If the reduced vision is due to an eye disease, you may be prescribed ocular medication or another treatment.

Visual Acuity FAQs

What does 20/20 vision mean?

20/20 vision is normal vision acuity (the clarity or sharpness of vision) measured at a distance of 20 feet. If you have 20/20 vision, you can see clearly at 20 feet what should normally be seen at  a distance. If you have 20/100 vision, you must be as close as 20 feet to see what a person with normal vision can see at 100 feet.

Does 20/20 mean perfect vision?

No. 20/20 vision only indicates the sharpness or clarity of vision at a specific test distance. Other important vision skills, including peripheral awareness or side vision, eye coordination, depth perception, focusing ability and color vision, contribute to your overall vision ability.

Is 15/15 vision better than 20/20 vision?

No. 15/15 vision means normal sharpness of vision at 15 feet, just as 20/20 indicates normal sharpness of vision at 20 feet. For  onsistency, doctors of optometry in the United Sates use 20 feet as the standard for measuring sharpness of vision. Other countries express visual acuity in their own way. In England, for example, doctors of optometry express visual acuity in meters (6/6 is considered normal).

Why do some people have less than 20/20 vision?

Many factors affect visual acuity. Vision conditions, like nearsightedness, farsightedness, or astigmatism, or eye diseases affect clarity of vision.

Will clarity of vision vary with distance?

Some people can see well at a distance but cannot bring nearer objects into focus. The condition can be caused by hyperopia (farsightedness) or presbyopia (loss of focusing ability). Others can see items that are close but cannot see items that are far away. This condition may be caused by myopia (nearsightedness).

If my vision is less than 20/20, what can I do?

In a comprehensive eye examination, a doctor of optometry can diagnose what causes, if any, are affecting your ability to see well. In most cases, your doctor of optometry can prescribe glasses, contact lenses or a vision therapy program that can help improve your vision. If the reduced vision is due to an eye disease, your doctor might prescribe eye medication or another treatment.

Find a Doctor of Optometry

Find a Doctor of Optometry

Related Articles

Visual Acuity

Visual Acuity is the clarity or sharpness of vision.

Healthy Vision and Contact Lenses

Safe contact lenses use provides an effective form of vision correction. Contact lenses prescribed by a licensed doctor of optometry are worn safely and comfortably by millions of people worldwide and have a long history of providing wearers with a safe and effective form of vision correction.

Types of Contact Lenses

There are many types of contact lenses, each with its own advantages and disadvantages. Learn more about each type with our side by side comparison.