The phrase “20/20 vision” has come to mean clear or perfect vision in the minds of many people, which is why you’ll hear “hindsight is 20/20”, meaning you can see things clearly when looking back at time and events, or you may have been in a conversation with a friend who happily tells you they had an eye exam and “have 20/20 vision”, indicating that they are proud of their great eyesight.
So, what exactly does it mean to have 20/20 vision? If someone has 20/20 vision, does it mean their vision is “perfect”?
What is 20/20 Vision?
The AOA (American Optometric Association) defines 20/20 vision as 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.[1]
Is 20/20 Vision Considered Perfect Vision?
20/20 vision is not considered perfect vision. It is considered normal vision.
If you have 20/20 vision, it means you can see clearly at 20 feet what should normally be seen at that distance. 20/20 vision does not account for other important visual skills, including peripheral vision, depth perception, eye coordination, ability to see colors, and ability to properly focus on objects.
Why Do Some People Not Have 20/20 Vision?
People who have hyperopia (farsightedness), myopia (nearsightedness), astigmatism, or certain eye diseases can’t see clearly at 20 feet what should normally be seen at that distance. During a comprehensive eye exam, we measure visual acuity and if we determine you cannot see clearly at 20 feet what should normally be seen at that distance, we will prescribe the appropriate treatment to help you achieve normal visual acuity.
If your vision isn’t 20/20 and is due to being farsighted, nearsighted, or having astigmatism, a prescription for eyeglasses or contact lenses may be sufficient treatment so that you experience 20/20 vision. If your vision isn’t 20/20 and is due to eye disease, medication may be prescribed, or a custom treatment plan based on your individual eye health needs.
Do People with 20/20 Vision Need Glasses?
Most people who have 20/20 vision will not need to wear eyeglasses until around the age of 40 or so, when vision starts to worsen when looking at things close-up. As we age, the lenses on the front part of our eyes harden and become less flexible, and this leads to a gradual loss of the eyes’ ability to focus on nearby objects. People over 40 or so may still be able to see 20/20, but since their vision when looking at things nearby gets blurry, they may need to wear reading glasses or glasses with special progressive lenses. Another scenario in which a person with 20/20 vision will wear eyeglasses is if they work in front of a computer all day and would like to have lenses with blue-light blockers, or if their eyes are out of alignment and they need special lenses to help them properly focus to eliminate painful side effects such as headaches, neck and shoulder pain, and fatigues.
If I Have 20/20 Vision, Do I Still Need an Eye Exam?
If it’s been more than a year or two since your last eye exam, you may be surprised to learn that your vision has changed. Even if your last eye exam determined you have 20/20 vision and you feel that you can see fine, comprehensive eye exams are about more than your visual acuity. We fully examine your eye health, too, and can spot signs of diabetes, high blood pressure, and more, of which you may not even be aware.
[1] The AOA (American Optometric Association)
