The Myth of 20/20 Vision

Published on
June 9, 2022

The majority of us mistakenly believe that 20/20 on the E chart means everything is fine with our vision when we actually need to use 17 visual skills every single day.

What does 20/20 mean? 

The top number 20 refers to the distance between a person and the chart when they are being tested. The bottom number indicates the size of the letters that the individual is able to read on that chart. As distance is measured in feet and inches in the United States, the quantity 20 refers to the number of feet between a patient and the standard E chart an optometrist uses to test visual acuity. In turn, how well you can read numbers and letters on the chart from this distance determines how well you can see clearly. The UK and other countries that are using the metric system refer to 20/20 vision as 6/6 vision, which indicates the distance in meters between patient and chart rather than feet.

Is your vision perfect if you have 20/20 vision?

Therefore, if someone's vision is 20/20, they probably don't need glasses, contact lenses, or any type of magnification to see clearly. It doesn't mean that they don't have any other types of underlying vision problems since their vision may not be perfect. You may need corrective lenses, however, if you are nearsighted (meaning, you see well when things are close up), farsighted (you can see clearly at a distance), or a combination of both. In spite of whether or not you need glasses, it is important to remember that your vision cannot simply be determined by how well you read the E chart.

If 20/20 is not a true indicator of your vision, how do you know if you have a vision problem?

School Eye Testing

Schools can conduct vision screenings, but they are not the end-all and be-all of vision screening, although they can provide a good indication of a student's vision and the need for help. These tests cannot detect a wide range of vision problems, which is why using them to prove someone has "perfect vision" is not appropriate. According to the College of Optometrists in Vision Development (COVD), the most common visual problems are not related to visual acuity. A school vision screening only accounts for 4% of a comprehensive eye exam, according to the American Optometric Association. In any case, you should take the results of any school vision test to your eye doctor, so they can compare what they see in the office with what was recorded in school.

Eye Function

All children entering school should receive a functional eye exam (also known as a developmental eye exam). A functional vision exam is important for older children and adults who have blurred vision, headaches, neck strain, dizziness, difficulty recalling, reading comprehension, or other significant visual problems.


Schedule a functional eye exam at Amplify EyeCare Chattanooga

In the event that your child scored 20/20 on a vision test but has learning problems, reads below grade level, has poor hand-eye coordination, or struggles to pay attention, then it may be a good time to schedule a functional eye exam. Dr. McBryar, a pediatric optometrist, and her team will be happy to examine your child for any underlying vision problems.

You can reach us at (423) 710 3965.


Vision therapy is well worth the response, time and effort. Our Son had a hard time focusing and writing neatly. After vision therapy Seth could complete a task in half the time if previously took. His abilities to focus improved greatly and so did his handwriting.

Also, he was better at listening. As a parent, we wanted learning to be fun for our Son, and vision therapy made this possible.

Amanda T.

Vision Therapy is well worth the expense, time and effort. Our son had a hard time focusing handwriting neatly. After vision therapy Seth could complete a task in half the time it previously took his abilities to focus and improved greatly and so did his handwriting.

Also, he was better at listening. As a parent you wanted learning to be fun for our son and vision therapy made this possible.

Alexa H.

Vision Therapy has given or son the tools he needs to be able to scan and read the written word more effectively and efficiently.

He love working with John and these working sessions give him the motivation to gladly work on his homework assignments.

It amazed us to see the difference in the tracking of his eyes and along a line of it's from the beginning to the end of the treatment.

Dr. McBryar , Kristen and John  are all marvelous and we would recommend them to anyone I only wish that we would have found them sooner!

Charlotte M.

Prior to coming to the institute for vision development my son complained of daily headaches. Therapy has eliminated his headaches completely. I love knowing my son is able to learn pain-free for the rest of his life because of the work that has been done over just a few weeks in this office. He he absolutely loved coming that didn't even feel like going to a doctor or therapy. We are grateful for the relief he was able to find by coming here.

Thank you!

Olivia C.

Seems much less frustrated with life

Reads non-stop and fast

Spelling abilities have been hugely improved

Seems much more confident

Thank You!!!

Kelly O.

When we first came to the practice, my son did not have huge issues, but lots of small ones- trouble with reading, sports (hitting the baseball consistently), coordination, etc- that were not easily detectable,but when put together presented issues. The staff here were all very professional and loving towards him. While I was concerned in the reading, my son was concerned with the athletic side. Seeing improvement night off the bat gave him confidence that i have nor seen in him and made him want to not only Come to therapy, but also made him want to work hard. He has surpassed his grade level and above in reading and hit his first home run this year! Thank you!!!

Alice M.
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