What is 20/20 Vision?

    SAN FRANCISCO, CA, June 28, 2009 /24-7PressRelease/ -- The term 20/20 vision is used to define perfect vision. In countries which use the metric system it is known as 6/6 vision, referring to meters instead of feet.

20/20 vision describes normal clarity and sharpness of vision (visual acuity, also called Central Vision) at a distance of twenty feet from the Snellen eye chart. That is the chart with one large letter at the top and lines of letters below which become smaller towards the base of the chart. One of those lines is defined as the 20/20 line for testing purposes.

The first number in 20/20 is a baseline figure, referring to a standard distance from the chart of 20 feet. The second number defines an individual's vision.
-Individuals with 20/20 vision can see the designated testing line clearly from a distance of twenty feet
-Someone with 20/100 vision would have to be twenty feet from the chart to clearly see what a person with 20/20 vision can see from a distance of 100 feet. In other words, this individual is myopic, with blurry distance vision.

20/20 Vision Not Necessarily Perfect
Visual acuity is just one aspect of vision. It is a quantitative measurement of how much a person can see. It expresses whether a person is nearsighted, farsighted or astigmatic. Those three conditions are refractive errors where the eyes are not refracting (bending) incoming light well enough to give the person clear vision at all distances. They are also known as the three Lower Order Aberrations and they express how much a person can see.

There is also a qualitative assessment of vision which measures a person's Higher Order Aberrations. These are not distance-related, but have to do with how well a person sees. Examples are:
-Halos around light sources
-Spiky starbursts around lights
-Glare in dim light
-Ghosting (faint duplicate images)

Until Wavefront technology brought us Custom LASIK, these vision features were not measured. Now a Wavefront diagnosis measures and records them in the form of colored 3-D maps. Treatment is therefore more precise, being based on a more detailed diagnosis.

Other Important Aspects of Vision
Before you have any laser vision correction your eye surgeon would assess your eyes in these respects:
-Peripheral or side vision
-Eye coordination
-Depth perception
-Color vision

How do I Know if my Vision is 20/20?
If you can see clearly at all distances without any glasses or contact lenses, you probably have 20/20 vision. Any time you go for an eye test to get glasses, your visual acuity will be tested to determine your glasses prescription.

If your vision is not 20/20, don' t worry. It can be corrected. A hawk's vision is about 20/2, and no human being can ever match that. It means that the hawk can see at 20 feet what we must be only two feet away to see clearly.

If you are interested in LASIK, why not contact experienced LASIK surgeon Gary Kawesch to correct your visual difficulties and see the world in a whole new light.

Source: Dr. Gary Kawesch
Website: http://www.lasikdocs.com

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