What is 20/20 vision?
In a previous post we described exactly what 20/20 vision is and what it means. In this post we explore whether 20/20 is really perfect Vison, or is it possible to see better than 20/20?
Before we answer that question, let’s do a quick recap of what 20/20 means. Although it looks intimidating, it’s really just simply a comparison. A comparison between what you can see as compared to what a person who has normal vision sees. Now you ask, what is normal? In this case normal suggests average. The vision of the average Joe, not an athlete, not a sharpshooter but the average person off the street.
So what is 20/20? Well, let’s look at 20/40 to begin with. 20/40 indicates that you can see from 20 feet the exact same target that our normal Joe can see from 40 feet. Therefore, you need to be closer by 20 feet (40-20=20) meaning you don’t see as well as our average Joe. You need to be closer to see the same target.
If your vision is 20/8, then you are able to see from 20 feet what the average Joe can see from 8 feet. This means you can be 12 feet further away (20-8=12) and still see the target correctly. That makes you better than normal. If the top number of our vision fraction is bigger than the bottom number you have better than normal vision. If the bottom number is larger than the top number you have less than normal vision.
That brings us to 20/20 which you now know means you are normal. You can see from 20 feet what the normal person can see form 20 feet.
What is the best vision humanly possible?
The best vision humanly possible is considered to be 20/8. That means you can stand 12 feet further away from a target, than the average Joe, and still see it correctly. Now, there are many factors that make 20/8 the best vision possible. Some of those factors include the target used to test. For example, it is easier to see pictures than it is to see letters.
If pictures are used then vison may actually test better than 20/8. Also, the age of the subject is important. Normal we don’t expect kids to be able to see 20/20, let alone 20/8 until about age 7 years. So as you see there are many factors that influence that 20/8 number.
Why is the best vision 20/8?
That is a bit easier to answer. Think about a television or a phone screen. You have heard about “pixels” and the more pixels a screen has the better the picture? Well, the eye is not much different. The more pixels, the smaller the target we can see. Each pixel in actually a photoreceptor. A photoreceptor is simply a cell that can translate light into an electrical signal to send to the bran. In the human eye we have two types of photoreceptors.
We have cones which are sensitive to color and we have rods that simply sense light or dark. The cones are packed densely together and are mostly found in our central vision. The rods are packed less closely and form (in general) our peripheral vision. If light were to fall between two cone cells, it would not stimulate anything and would not be seen. Also, there are other cells that connect the photoreceptors to the brain. These cells are called ganglion cells. The number of ganglion cell connections also plays a role in how small a target we are able to see.
How to see better than 20/20
So, if you’ve read this far, you must be interested in seeing better than 20/20. It is very possible that you may be better than average considering that half the people are better than average! What can you do to be sure you are in the better half? Well, there are two main factors that influence how well you can see.
The first factor is what you eye does and send to your brain. For most people this is the issue. The issue being focus. If you are nearsighted or farsighted or have astigmatism or any combination – you won’t be seeing at your maximum. In this case, you may need glasses or contact lenses to fix the focus and achieve vision better than 20/20. It is certainly possible, and it requires a very careful exam by your eye doctor. With care, your eye doctor may discover a very small prescription which when used provides better vision than 20/20.
The second factor is your brain. More specifically, the vision portion of your brain. If this is the limiting factor, then it may be more difficult to get vision better than 20/20. There are people with amblyopia (lazy eye) who have less than 20/20 vision due to incomplete development of vision. There are also normal people who never developed maximum vision and are locked at 20/20 vision. Recently there has been some research about improving what the brain can see. This work is still somewhat early and seems to work in some individuals, but not in everyone.
The Internet speed and best vision
Think about a computer hooked up to the internet. If you have the latest and greatest computer and a high speed fiber optic internet connection, your web pages will load almost instantaneously. That speed is just like having 20/8 vision. If you have the latest and greatest computer but a dial up slow internet connection, your web page will load very slowly. That is the same as having less than normal vision.
The same would happen if you had a very fast internet connection but an old computer. the web pages would be very slow as well. You would need to make sure both the computer and the internet connection were top notch. Well, the same for the eyes. If the computer is slow (the brain) vision wont be maximal. if the internet signal is slow (the eye) vision won’t be maximal. In this case, its easier to upgrade the “internet speed” by using glasses or contacts. It is harder to upgrade the brain (the computer) for optimal vision.
How this relates to sports performance
Knowing what your vision is can help you perform in your sport. Even better, knowing how your vision compares to the average elite athlete in your sport can be even more useful. The best option is to have an exam by a sports vision specialist. The specialist can make sure you are seeing your best, for maximum performance.
Several studies have linked visual ability to athletic performance. Additionally, I am hard pressed to find a successful athlete who competes with their eyes closed. Vision is the basis for any motor action in sports. Vision guides that motor action to success!
It is possible to see better than 20/20 as long as your eyes are your brain are operating at 5G speeds!