What is 20/20 vision?
The definition of 20/20 vision is the ability to see an object clearly from 20 feet away. Others with normal vision can also see an object clearly at that distance. 20/20 vision refers to “normal” vision, not “perfect” vision.
Visual acuity is a term that means clarity or sharpness of vision and that the objects you see are crisply outlined and not blurry.
Calling normal vision “20/20 vision” is true for eye care professionals in the U.S., but not everywhere in the world. In Europe and elsewhere, eye care professionals would say that normal vision is 6/6 vision because they use the measurement of 6 meters instead of 20 feet.
Is having 20/20 vision the only thing that matters when it comes to vision?
Having 20/20 vision doesn’t include other factors like peripheral vision (seeing what’s on either side of you), your ability to see colors or your depth perception.
Depth perception is also called stereopsis. It refers to being able to see how long, wide and deep an object is, along with how near or far it is from you.
Color blindness means that you don’t see colors the same way other people see them. It’s also called color vision deficiency or poor color vision.
Can your vision be better than 20/20?
Yes. Having 20/20 vision means you have normal or average, vision. Some people have vision that’s better than 20/20, like 20/15 vision or 20/10 vision. This means that you can see something 20 feet away (like a line on an eye chart) that most people can see when they’re 15 feet away (20/15) or 10 feet away (20/10).
Why is having good vision so important?
- Safety: Average activities, such as driving, biking, or even walking can be dangerous for you and others if you can’t see properly. In most U.S. states, you have to have at least 20/40 vision or better to be able to drive without corrective lenses. Having vision that measures 20/200 with correction is the definition of legal blindness in terms of acuity (clarity of vision). Another part of the definition includes peripheral vision.
- Comfort: Being able to see clearly allows you more freedom in your activities. Having good vision means that you won’t have to squint, whether you’re at the back of the classroom or at the front of the movie theater.
- Reading ease: Good vision helps you read more comfortably for work, learning or enjoyment.
- Quality of life: With good vision, you may have a better quality of life.
How common is 20/20 vision?
Most people don’t have 20/20 vision without eyeglasses or contact lenses. One estimate suggests that only about 35% of all adults in the U.S. have 20/20 vision without corrective lenses.
Symptoms and Causes
What causes you to have less than 20/20 vision?
There are several eye conditions that can cause your vision to be less than the average of 20/20. These include refractive errors:
- Farsightedness (hyperopia).
- Nearsightedness (myopia).
- Presbyopia. This refers to being unable to focus on objects that are close to you. It generally happens as you get older.
- Astigmatism. In this condition, some part of your eye has an irregular curve.
There are many different conditions that affect your eyesight, including those that are systemic (throughout your body) and those that affect only your eyes.
Everyone needs to have regular eye examinations. However, your provider is more likely to stress the need for regular eye examinations if you have disorders like:
- Multiple sclerosis.
- Thyroid issues.
- Macular degeneration.
- Diseases that affect your cornea. The cornea is the clear “window” of the eye that offers protection and helps your eye focus.
Diagnosis and Tests
What tests are used to determine if you have 20/20 vision?
Your eye care provider will begin by giving you an eye exam. There are many parts to an exam.
Your eye care provider will ask you to read letters off a chart (known as a Snellen chart). You’ll first read with one eye covered, then the other eye covered and then with both eyes. Your provider can then measure how close (or how far away you are) from 20/20 vision in each eye.
The results will give your eye care professional information about your sight and what prescription you may need to correct it. Visual acuity tests are fairly simple and non-invasive. They can be performed by a technician, nurse, optician, optometrist or ophthalmologist.
Management and Treatment
How does your provider treat vision that doesn’t meet the 20/20 standard?
If you need vision correction, there are safe and affordable choices. It’s important to choose a corrective vision method that suits both your prescription needs and your lifestyle.
- Eyeglasses: the most traditional form of vision correction is with spectacles or eyeglasses. Glasses work by bending light so it’s in focus on the retina. Eyeglasses are practical, affordable and safe.
- Contact lenses: Contacts are more suitable for those with an active lifestyle. Contacts work the same way as glasses but stay in place better during physical activities. Some people also have cosmetic reasons for preferring contacts to glasses. Also, you can correct certain refractive errors or eyeglass measurements better with contacts than with glasses. Being outdoors means being in the sun, and contacts allow you to wear sunglasses at the same time. There are many different brands, colors and materials. Your eye care provider will discuss options and fit you with the contacts that work best for you.
- Corrective surgery: Vision correction surgery is performed by changing the refractive, or light-bending, properties of the eye. Refractive surgery is functional because it restores your ability to see objects clearly without wearing glasses or contact lenses. Some people may not be good candidates for corrective surgery, but the results are meant to be long-lasting. You don’t have to deal with daily cleaning of lenses or with repairing glasses.
- Eye drops: The FDA has approved pilocarpine hydrochloride ophthalmic solution (VUITY®). These eye drops can treat presbyopia in adults.
How can I reduce my risk of having less than 20/20 vision?
You can’t change the eyes or the eyesight you’re born with, but you can do certain things to prevent vision loss. These things include:
- If you smoke or use tobacco products, ask your provider for help quitting.
- Have regular eye examinations.
- If you have diabetes, it’s important to pay attention to your blood glucose levels and to maintain good blood pressure.
- Speak to your family members about any family history of eye disease. Let your eye care provider know what you find out.
- Try to reach and maintain a healthy weight for yourself. Having obesity can be a risk factor for diseases that can affect your eyes.
- Wear protective goggles and safety glasses when you’re working or participating in contact sports. Wear sunglasses in bright light.
- Rest your eyes. If you work at a screen, try what some people call the 20-20-20 rule. Every 20 minutes, look at something that’s 20 feet away for 20 seconds. Keep blinking so your eyes don’t get dry.
- Keep your hands clean when you put your contact lenses in. Make sure your lenses are clean.
- Eat a healthy diet that includes plenty of fruits and vegetables. Studies indicate that salmon, halibut and tuna may help keep your eyes healthy.
Outlook / Prognosis
What can I expect to happen to my vision as I get older?
Aging can affect your eyes, even if you’ve had 20/20 vision throughout your life. Many older adults find that they have trouble with close-up vision and may have trouble telling some colors apart. They may also find that their eyes don’t adjust as quickly to changes in light.
When should I see my healthcare provider?
You should see your healthcare provider for your regularly scheduled appointments. If you have any worrying changes in between your appointments, you should contact your provider. These changes may include:
- Eye pain.
- Blurry vision.
- Headaches due to eye strain.
- Swelling of the eyes or the area around the eyes.
A note from Cleveland Clinic
Having 20/20 vision means that your vision is normal. If you don’t have 20/20 vision, your eye care professional will help you find out what condition may be affecting your vision. They’ll also help you find a way to improve your vision, such as wearing glasses or having eye surgery. Keep your scheduled eye appointments and follow recommendations. You can do many things to prevent vision loss.
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