Is 20/20 Vision Perfect Vision?
What does the phrase 20/20 vision actually mean? We know contacts and eyeglasses help us have 20/20 vision. When an individual has 20/20 vision, they can see what an average person can see on the eye chart from 20 feet away.
What does 20/20 vision mean?
The eye chart you read at the eye doctor’s office measures visual acuity or sharpness of vision. The bottom number refers to the distance in which someone with normal eyesight can read the same line. The top number indicates the range in feet from the chart. If you have 20/30 vision, it shows your vision is worse than the average. A vision of 20/30 means that when you stand 20 feet away from an eye chart, you can read letters that the average person can read from 30 feet away. Therefore, your vision is not as good as someone with 20/20 vision, which is the standard for measuring vision.
Contrary to popular belief, 20/20 vision is not perfect vision. Someone with 20/15 vision has sharper vision than the average. With 20/15 vision, you can see the chart at 20 feet away that the average person sees at 15 feet away. Ordinarily, the goal of your optometrist or ophthalmologist is to correct a person’s vision with glasses or contacts to 20/20 vision.
Why is 20 feet considered the baseline?
When you are viewing an object 20 feet away, your eye is relaxed and in its normal shape. The eye does not have to bend light rays from the object to focus the image on the retina in the back of the eye.
Only around 35 percent of all adults have 20/20 vision without the assistance of contact lenses, glasses, or corrective surgery. About 75 percent of adults enjoy 20/20 vision with corrective measures. Most states require visual acuity of 20/40 or better to obtain an unrestricted driver’s license, and individuals are considered to be “legally blind” if their corrected vision is 20/200 or worse.
Vision exams for children
According to the American Academy of Ophthalmology, visual acuity in children should be tested when the child is old enough to participate in an eye exam with the eye chart. According to associate professor of ophthalmology and director of Comprehensive Ophthalmology Services at University of Iowa Hospitals and Clinics, Tim Johnson, MD, some children begin to lose their 20/20 vision as young as 8 or 9. After that time, most visual acuity remains stable until they reach the age of sixty or seventy when they will see a slight decrease.
Middle age vision problems
As you reach middle age, you will not see a decrease in your visual acuity, but you may see a change in your near vision. The lenses in your eyes become less flexible, and it is harder to change focus from far away objects to closer objects. This normal part of aging is called presbyopia. You will notice it as you begin holding reading materials farther away in order to read them clearly. Bifocals or reading glasses are an easy fix to the issue.
The American Academy of Ophthalmology suggests you get a baseline eye exam at age 40. This is the time when changes may occur, and signs of disease can be found. The evaluation provides a greater opportunity for the preservation of vision and early treatment. An ophthalmologist will recommend the necessary intervals for follow-up exams, based on the results of the initial screening. The eye disease screening is an excellent reminder to maintain eye health.
Schedule Your Eye Exam with Northern Vision Eye Care
Regular eye exams are important for great vision and also may reveal for any problems that do not show early symptoms. Our doctors at Northern Vision Eye Care in Traverse City, Michigan are trained to provide the best medical and surgical eye care you may require. We will serve you with technology, experience, and skill. Contact us today to schedule your eye exam.