20/20 Vision Explained

In General, Health, Misc, Personal on February 4, 2007 at 9:53 pm

Visual acuity is expressed as a fraction. The top number refers to the distance you stand from the chart. This is usually 20 feet. The bottom number indicates the distance at which a person with normal eyesight could correctly read the line with the smallest letters. Normal vision is considered 20/20. If your vision is 20/40, the line you correctly read at 20 feet could be read by a person with normal vision at 40 feet.

If your optometrist says you have 20/60 vision, that means you are able to discriminate characters at 20 feet away from an eye chart that a person with normal acuity can see at a distance of 60 feet.

Of course, just because 20/20 vision is normal doesn’t mean it’s perfect. A small percentage of the population is blessed with vision better than 20/20, and just recently researchers unveiled corrective lens that offered vision.


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  1. So the chart continues (lines 9, 10, and 11. I assume that means you can have better than 20/20 like 20/10?

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