When a person has 20/20 vision, they can see with standard visual acuity. This refers to the sharpness or clarity of an object at 20 feet away.

The general standard that corrective measures try to achieve is 20/20 vision. This means that people can see objects, letters, numbers, or other things with the same clarity as an average adult when standing 20 feet away from the item.

Optometrists — doctors specializing in eye health and care — use eye charts to diagnose a person’s visual clarity. When addressing visual acuity, the goal of treatment is to help people achieve 20/20 vision.

Some people may have a better vision than 20/20, while others may have less than 20/20 vision. For example, 20/30 vision means an individual can see an object 20 feet away with the same clarity that most people can see at 30 feet.

This article explores what 20/20 vision is, vision diagnosis, maintaining 20/20 vision, causes and treatments of less than 20/20 vision, and frequently asked questions.

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According to the American Academy of Ophthalmology (AAO), 20/20 vision means that a person can see an object with clarity or sharpness at 20 feet away. It is also the standard that corrective lenses and procedures typically aim to achieve.

Despite experts describing 20/20 vision as “perfect vision,” most people usually achieve it only with corrective measures.

Research suggests that even with corrective measures, such as glasses, the estimated number of people who achieve 20/20 vision is about 75%. Estimates state that only about 35% of people have 20/20 vision without correction.

Lower than 20/20 vision

A higher second number indicates worsening vision, while a lower number indicates better vision. For example, an individual with 20/100 vision can see objects clearly at 20 feet away than the average person can see at 100 feet away.

Better vision than 20/20

A person can have better than 20/20 vision. Doctors consider 20/15 vision very good or above average. An individual with 20/15 vision can see objects clearly at 20 feet away, while most people must be only 15 feet away to see those same objects.

People typically have 20/15 vision only if it occurs naturally. The goal of corrective treatments is to reach 20/20 vision.

An optometrist makes the diagnosis using eye charts or during a comprehensive eye examination

Ophthalmologists and optometrists diagnose eye conditions. Opticians use refraction to help make the correct glasses.

Nurses, primary care doctors, pediatricians, and most school screenings may have an eye chart to help determine acuity, but they are not diagnosing an eye condition.

Vision can change as a person ages. People who reach middle age often notice changes in their near vision. This can make it more difficult to see objects up close or make it more challenging to switch focus from far to near or near to far.

When to have eye exams

Children should get their eyes examined once they are old enough to cooperate with an eye exam. Certain researchers suggest children can lose their vision as early as 8 or 9.

However, children often need glasses before that, so experts recommend having an eye exam before starting school. The pediatrician often checks for eye alignment before age 5.

According to the American Optometric Association (AOA), the recommended examination frequency for children is:

AgeNo symptomsAt-risk and symptomatic
birth through 2once at 6–12 months of ageonce at 6–12 months of age or as recommended
3 through 5at least once at least once or as recommended
6 through 17before first grade and annually after thatbefore first grade and annually after that, or as recommended

A person with no history of eye issues should get a baseline disease screening by an ophthalmologist at age 40 and then periodically, based on the exam’s findings.

The AOA recommends the following frequency for adults:

AgeNo symptomsAt-risk
18–39at least every two yearsat least annually or as recommended
40–64at least every two yearsat least annually or as recommended
65 and olderannuallyat least annually or as recommended

Learn more about eye health from our dedicated hub.

A person may not be able to prevent vision loss, but there are some steps people can take to help reduce their risk.

According to the Centers for Disease Control and Prevention (CDC), a person can take the following steps to help protect their vision:

  • scheduling a comprehensive eye exam
  • learning their family history of eye disease
  • maintaining blood sugar levels
  • eating a balanced diet
  • avoiding or quitting smoking
  • maintaining a moderate weight
  • wearing protective eyewear to prevent injury that may affect vision
  • resting the eyes after looking at screens following the 20-20-20 rule: every 20 minutes, focus on an object 20 feet away for 20 seconds
  • wearing sunglasses when outside

People who wear corrective lenses should also take steps to properly care for their glasses or contacts and replace them as directed. This can include keeping the contacts clean to help prevent infections.

A person may develop less than 20/20 vision for several reasons.

Vision conditions can affect the clarity of vision, such as:

Some more advanced conditions that can cause people to have poor vision include:

Treatment for 20/20 vision can vary.

Common correction methods include using glasses or contacts, often known as corrective lenses. Both glasses and contacts can help achieve 20/20 vision.

Laser treatments can help correct vision. The procedure helps correct vision conditions.

The following sections provide answers to commonly asked questions about 20/20 vision.

Do people with 20/20 vision have to wear glasses?

A person may need glasses for other eye issues unrelated to visual acuity. A doctor may prescribe glasses to treat anisometropia (a difference in focus between the two eyes) or astigmatism (an atypical lens curvature).

What to expect when you are older if you have 20/20 vision when younger?

The AAO states that people should have eye examinations at least every decade if they do not have any other eye issues. Recommended examination frequency varies for children and adults.

The term “20/20 vision” refers to the adopted standard of vision correction that most people can achieve. However, an individual can have a worse vision or better vision. Most people need some form of corrective lenses to achieve 20/20 vision.

An optometrist can test a person’s vision using eye exams. They can recommend treatments, including glasses, contacts, or corrective procedures.

People will need regular eye exams as they age. This can help protect their vision and prevent potential eye conditions or diseases.