The Myth of 20/20 Vision

Are you aware that 20/20 eyesight measures only one component of our vision? Though we often think 20/20 vision is perfect, is it really?

Amplify Eyecare Chattanooga

What is 20/20 Vision?

Most of us grew up equating 20/20 vision with perfect vision and at a certain point, it seemed that having “the best” eyesight was a goal for which we needed to strive. However, many years of education and learning later have taught us that there is no such goal. Perfect vision, it seems, is a myth. And the biggest surprise of all is that 20/20 vision is merely average. In fact many competitive athletic programs screen their athletes to assess much more than 20/20 vision including visual skills such as spatial awareness, depth perception, hand-eye coordination, color contrast, and peripheral vision.

When we talk about 20/20 vision, it’s important to know what the numbers mean and how they've come to define how well, or not, we see. In the United States, where distance is measured in inches and feet, the number 20 represents the number of feet between patients and the standard E chart optometrists use to test visual acuity. In turn, your ability to see clearly is based on how well you can read the letters and numbers on the chart from this distance. In the UK and other countries that use the metric system, 20/20 vision is known as 6/6 vision, an indication of how many meters rather than feet, stand between patient and chart. 

The Snellen 20/20 fraction, named for the ophthalmologist who created this system, corresponds to two distinct factors. The top number of the fraction represents the distance between the patient and the chart, and the bottom number corresponds to lines on the chart. If for example, you can read the large E at the top from a distance of 20 feet, you have 20/200 vision. Because the system measures how well people see on average, 20/200 actually  indicates rather poor visual acuity. To further clarify, 20/20 vision is a measure of how well the average person sees, not the one with unrealistically “perfect” vision.”

What 20/20 Vision Means For You

If you have been told you have 20/20 vision, chances are you don’t need glasses, contact lenses, or magnifiers to see or read clearly. If however it is determined that you are nearsighted (meaning, you see well when things are close up), farsighted (you’re able to see things in the distance clearly), or a combination of the two, you’re likely to need corrective lenses. Regardless of whether or not you need glasses, it is important to remember that the sum total of your vision cannot be based on how well you read the E chart.

What 20/20 Vision Means For You
How to Determine if You Have a Vision Problem

How to Determine if You Have a Vision Problem

If 20/20 isn’t a true measure of how well your eyes work, how do you know when you have a vision problem?

School Eye Testing

Vision tests administered in schools are not the be-all, end-all to vision screening, but they can give you a good starting point to identify if your child sees and if they need help. It’s important to understand that these screenings cannot detect a number of visual deficits, which is why reliance on them as proof of “perfect vision” is highly discouraged. According to the College of Optometrists in Vision Development, the most common vision problems are not associated with visual acuity (20/20 vision).

Still, the results of any school vision test should be brought to your eye doctor, as they can compare what they see in-office to what’s been recorded in school.

Eye Function

If you’re experiencing blurred vision, headaches, neck strain, dizziness, have difficulty with recall, reading comprehension, or other significant visual functions, it is important you see our eye doctor for a functional vision exam. Although you or your child may not need corrective lenses, you may be a candidate for vision therapy. It is important not to place too much trust in a school screening that only assesses 4% of a functional vision examination; this screening will not reveal many vision problems.

Common Questions

Determining if you’re nearsighted, farsighted or both is just one way your vision is measured. There is a tremendous amount of behind the scenes communication that takes place between your brain and your eyes that needs to be tested and checked regularly. There are 17 visual skills that you need to have good vision, so getting glasses is only one part of a complex ocular puzzle.
You should always have your child (and yourself!) seen by an optometrist annually. Remember that passing a vision screening doesn't mean there aren't other problems. While it is great to do well on this test, you should know that it does not measure the skills your brain and eyes need for clear vision and for success in the classroom.
The Myth of 20/20 Vision
Dr. McBryar cartoon

The Importance of Eye Exams

It is important and, frankly, good practice to have your eyes, as well as that of your family members, checked at least annually. 20/20 vision isn’t about having “perfect” vision and doesn’t give you a full picture as to what your eyes can really do. Remember too, that if you or your child struggle with any key visual skills, it's best to contact our optometrist. It’s possible you’ll need glasses or perhaps vision therapy. Our eye doctor is the one who can guide you best and recommend the interventions that are right for you. To schedule a functional vision exam, please call (423) 710 3965. Patients looking for a functional vision exam visit our clinic from all over Tennessee, and we are proud to be a leading provider of functional vision services for patients from Hixson, Chattanooga, Cleveland, and Middle Valley. 

Related Articles


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.
1 2 3 10



The impact of screen time on dry eye: tips for prevention

According to a recent study, people who spend more than 2 hours a day on digital devices are 2.5 times […]

Read More

Chattanooga pediatric eye doctor shares how children with vision problems can struggle academically

Many people believe that good eyesight is simply the ability to read the "20/20" line on an eye chart, but […]

Read More

Is there a difference between a scratched eye and a scratched cornea?

Corneal abrasions, or scratched corneas, are a common occurrence and make up a significant portion of eye injury cases. In […]

Read More
see all blogs

Contact Us To Amplify Your EyeCare

Amplify EyeCare Chattanooga Logo

Working Hours

Monday - Tuesday
7:30AM - 5:15PM

Wednesday - Thursday
8:00AM - 5:15PM

Friday - Sunday

1043 Executive Drive Suite #101 Hixson, TN 37343
(423) 710 3966
Website Accessibility Policy
Safety protocols page
privacy policy
For Patients
Call Us
eyefile-adduserphone-handsetcalendar-fullarrow-uparrow-right linkedin facebook pinterest youtube rss twitter instagram facebook-blank rss-blank linkedin-blank pinterest youtube twitter instagram