TABLE OF CONTENTS
- Overview of how your eye works
- What does 20/20 vision mean?
- What does 20/40 vision mean?
- Is it bad to wear reading glasses when you have perfect vision?
- Maintaining healthy eyes
- Final thoughts
It is unquestionable how important and unique our eyes are. Equally as important is maintaining a healthy perfect vision. There are different grades of vision that everyone has ranging from 20/10, 20/20, 20/40, etc. The physical apparatus for gathering visual information-the eye—and the brain circuits that process this information are more complex than you may think. The brain devotes more space to vision than to all other senses combined.
Continue reading further to learn more about perfect vision and how to maintain a healthy vision.
OVERVIEW OF HOW YOUR EYE WORKS
When it comes to the eye, it’s all about light. Light reflects off an object, and if that object is in your field of view, it enters the eye. The first thing light touches is the thin veil of tears on the surface of the eye. Behind this is your eye’s front window, the cornea. This clear layer helps focus light. On the other side is liquid called the aqueous humor. It circulates throughout the front part of your eye and keeps the pressure inside constant.
After the aqueous humor, light passes through the pupil which changes in size to control how much light gets in further back. Next is the lens which works just like a camera to focus light. It adjusts shape depending on whether the light reflects off something near to you or far away. This light now pierces the center of the eyeball which is known as the vitreous. Its final destination is the retina, which lines the back of your eye similar to a screen in a theater or the film of a camera. This is where the focused light hits cells called photoreceptors. Signals from the photoreceptors travel along the nerve fibers to the optic nerve. Finally, the signals are sent to the visual center in the back of the brain. That is how you ultimately see light.
Summary: Light is reflected from an object, enters the eye, gets focused, is converted into electrochemical signals, delivered to the brain, and is “seen,” as an image.
WHAT DOES 20/20 VISION MEAN?
20/20 vision is referred to as the standard, or how a “normal” person sees. This means, that when you stand 20 feet away from an eye chart, you see what the normal person should see. The American Optometric Association states that a person with 20/20 vision can clearly identify a row of 9mm letters from 20 feet. Having 20/20 vision does not necessarily mean you have perfect vision. 20/20 vision is a term used to express normal visual acuity (the clarity or sharpness of vision) measured at a distance of 20 feet.
Visual acuity refers to your ability to discern the shapes and details of the things you see. It’s just one factor in your overall vision. Other important vision skills include:
- Awareness of side vision
- Eye coordination
- Depth perception
- Focusing ability
- Color vision
WHAT DOES 20/40 VISION MEAN?
If you have 20/40 vision, this means that you can see only as good as a normal person can see at 40 feet away from an eye chart. To clarify this a bit further, if you have 20/40 vision and a person is standing 40 feet from the chart and you are standing 20 feet from the same chart, you both see the same amount of detail on the eye chart.
The reverse applies if you have 20/10 vision. If you have 20/10 vision you are above average. You are better than the “normal” person and you have better than what is considered to be the standard 20/20 vision. With 20/10 vision, you can see at 20 feet, what a normal person can see at 10 feet from an eye chart.
IS IT BAD TO WEAR READING GLASSES WHEN YOU HAVE PERFECT VISION?
In general, wearing reading glasses shouldn’t damage your eyes no matter your level of visual acuity. You might want to wear them to make it a little easier to see text, especially if you do a lot of near vision tasks. However, if you’ve never worn magnifying lenses before, keep in mind that you may experience some discomfort until your eyes adjust. Make sure to have a comprehensive eye exam with an optometrist to get the right prescription for your needs.
MAINTAINING YOUR EYES HEALTHY
Every day, there are simple ways you can maintain your eyes healthy such as:
- Eating healthy: Nutrients like Omega-3 fatty acids, lutein, zinc, and vitamin C and E might help ward off age-related vision problems.
- Quit smoking: Smoking makes you more likely to get cataracts, damage to your optic nerve, and macular degeneration, amongst other medical problems.
- Wearing sunglasses: The right pair of shades will help protect your eyes from the sun’s ultraviolet (UV) rays. Too much UV exposure can increase your chances of getting cataracts.
- Look away from the computer screen: Staring at a computer or phone for too long can cause eyestrain, blurry vision, trouble focusing at a distance, dry eyes, headache, neck, back, and shoulder pain. Rest your eyes every 20 minutes.
- Visit your eye doctor regularly: Aside from it helping maintain your sight, eye exams can also find diseases, like glaucoma, that have no symptoms.
Due to our aging population, the number of blind and visually impaired people in the United States is estimated to double by 2030 and triple by 2050. Encouraging people to take care of their vision health as part of their overall health could significantly reduce that number and improve the quality of life for millions of people.
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