20/20 Vision

What is 20/20 vision?

20/20 vision is “normal” vision. It’s a measure of the clarity or sharpness of your eyesight when you’re 20 feet away from an object. Eye care specialists call this visual acuity. Having 20/20 vision means your vision is typical — it doesn’t mean your vision is perfect. And while 20/20 vision is considered “normal” vision, only 35% of people in the world have it without glasses, contact lenses or eye surgery.

When you take a visual acuity test, the first number is how far away you are from the object. In vision tests, this number will always be 20. That’s because this test places you 20 feet away from a target. The second number is how far away a person with normal visual acuity would have to be to see the object with the same clarity and sharpness as you.

For example, if you have 20/15 vision, you see an object that’s 20 feet away as clearly as most people would see it if they stood 15 feet away. This means your vision is better than normal. If you have 20/40 vision, what you see 20 feet away from an object is what someone with normal vision could see from 40 feet away. This means your vision is worse than normal since you need to be closer to the object to see it. If you have less than 20/20 vision without corrective lenses, there are many options available that can help you see things more clearly.

In places around the world that use the metric system, 20/20 vision is known as 6/6 vision. This is because they measure your ability to see an object clearly from 6 meters away rather than 20 feet.

Is having 20/20 vision the only thing that matters when it comes to eyesight?

Having 20/20 vision is important for seeing the world clearly, but other parts of vision are important, too. Those include:

• Color vision.
• Eye alignment, which you need for depth perception and 3D vision.
• Low-light or night vision.
• Peripheral vision.

Why is having good vision so important?

Having good eyesight is important for your safety. It also plays a big role in your quality of life, helping with work, social activities, hobbies and much more. And good vision can mean that you wear glasses or contacts. What’s important is that you see clearly enough — with or without correction — to interact with the environment and people around you.

Vision does more than help you void sharp corners. It helps keep your mind sharp so you can keep up with your everyday activities. It helps you read recipes when you cook, instructions on your medications or cleaning products, and signs on the road as you drive.

What tests are used to determine if you have 20/20 vision?

An eye care specialist will check your vision by giving you an eye exam. They commonly use multiple methods at different points during an eye exam, including:

• Visual acuity test. This test involves reading letters off a chart (known as a Snellen chart). There are also variants of the test that use shapes instead of letters.
• Retinoscopy. This involves testing your vision with different lenses to find what helps you see best.
• Autorefraction. This test involves looking into a machine (at an image like a house in a field or a hot air balloon at the end of a long, flat road). The machine automatically measures your vision prescription.

Why might I not have 20/20 vision?

The most common causes of vision that’s less than 20/20 are refractive errors. These are issues with the shape of your eyes that make your vision blurry, including:

• Farsightedness (hyperopia).
• Nearsightedness (myopia).
• Presbyopia (age-related loss of the ability to focus on close objects).
• Astigmatism.

Other eye conditions can also impact how well you see, including:

• Cataracts.
• Corneal diseases.
• Diabetes-related retinopathy.
• Glaucoma.
• Retinal diseases.
• Strabismus-type conditions like amblyopia (lazy eye).

It’s also possible — though less common — for your vision to be better than normal.

How is low visual acuity treated?

Many possible vision correction treatments are available if you have refractive errors. These treatments alter your vision to bring it as close to 20/20 as possible. They include:

• Eyeglasses.
• Contact lenses.
• Vision correction surgery.

Other conditions may require surgical or medical treatment plus eyeglasses or contacts. Even then, you may not have 20/20 vision.

Can I lower my risk of having visual acuity that’s less than 20/20?

There are several things you can do to maintain your eye health and reduce your risk of having decreased visual acuity. They include:

• Getting regular eye exams every one to two years (even if you don’t wear eyeglasses or contacts).
• Wearing eye protection to avoid eye injuries, and using sunglasses to limit the effects of ultraviolet rays on your eyes.
• If you use tobacco or nicotine products, talking to your healthcare provider about quitting.
• Getting proper nutrition (your eyes need several vitamins and minerals to work properly).
• Reaching and maintaining a weight that’s healthy for you.
• Washing your hands to help prevent germs and infections from spreading to your eyes.
• If you use contact lenses, following the prescribed care instructions as well as the replacement and wear schedule.
• Not ignoring eye symptoms or vision changes, especially ones that happen suddenly.
• Managing chronic conditions (like diabetes) to limit or prevent negative effects on your eyes.
• Resting your eyes as needed (especially if you do a lot of close-up focusing or look at a computer screen frequently). Use the 20-20-20 rule (take a 20-second break every 20 minutes to look at something at least 20 feet away).