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. 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. It’s just one factor in your overall vision. Visual acuity refers to your ability to discern the shapes and details of the things you see. 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. Having 20/20 vision does not necessarily mean you have perfect vision. The American Optometric Association states that a person with 20/20 vision can clearly identify a row of 9mm letters from 20 feet. This means, that when you stand 20 feet away from an eye chart, you see what the normal person should see. WHAT IS 20/20 VISION MEAN?Ģ0/20 vision is referred to as the standard, or how a “normal” person sees. 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. ![]() Finally, the signals are sent to the visual center in the back of the brain. Signals from the photoreceptors travel along the nerve fibers to the optic nerve. This is where the focused light hits cells called photoreceptors. 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 light now pierces the center of the eyeball which is known as the vitreous. It adjusts shape depending on whether the light reflects off something near to you or far away. Next is the lens which works just like a camera to focus light. It circulates throughout the front part of your eye and keeps the pressure inside constant.Īfter the aqueous humor, light passes through the pupil which changes in size to control how much light gets in further back. On the other side is liquid called the aqueous humor. Behind this is your eye’s front window, the cornea. The first thing light touches is the thin veil of tears on the surface of the eye. Light reflects off an object, and if that object is in your field of view, it enters the eye. When it comes to the eye, it’s all about light. The brain devotes more space to vision than to all other senses combined.Ĭontinue reading further to learn more about perfect vision and how to maintain a healthy vision. The physical apparatus for gathering visual information-the eye-and the brain circuits that process this information are more complex than you may think. There are different grades of vision that everyone has ranging from 20/10, 20/20, 20/40, etc. Equally as important is maintaining a healthy perfect vision. This is a growing problem that must be addressed.It is unquestionable how important and unique our eyes are. Vision challenges are also largely related to public health concerns such as access to care, health inequalities, cultural competency, healthy literacy, etc. ![]() Eye health problems have a strong correlation to other public health concerns (diabetes, smoking, depression, falls, etc.). Our eyesight is highly valued it is central to success in school and work, as well as in socialization and retaining independence. Those individuals who show any symptoms of eye disease, including common risk factors such as diabetes, high blood pressure, or family history of eye disease are encouraged to consult with an eye care provider as early as possible to determine how frequently they should be examined. This message does not aim to replace recommendations for earlier eye care to treat previously existing disease or injury, or for vision examinations for eye glasses or contact lenses. ![]() One common eye problem, presbyopia, is a decreased elasticity of the lens due to advancing age which moves the near point of vision farther from the eye, making it difficult to focus on near objects (farsightedness). This is an age when indicators of reduced vision and/or poor eye health begin to become more prominent. Its message is simple: Absent previous signs, symptoms or risk factors, Prevent Blindness encourages all Americans to get a baseline eye exam by an ophthalmologist or optometrist at the age of 40, and regular eye care thereafter as directed by your eye care provider. “20/20 at 40” is a Prevent Blindness national public awareness program, encouraging working-age adults to take control of their own eye health.
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