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We wanted a clear, focused answer to your question, so we headed over to Yahoo! Health and searched on "vision." There were four matches in the search results -- we picked the "visual abnormalities" link. After reading through the information, we didn't find a mention of 20/20 vision so we looked around for other links. We clicked on a few but had little luck until we spotted "visual acuity" and, ultimately, the answer. 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. We didn't want to be myopic, so we headed to the front page of Yahoo! and searched on "visual acuity" (using quotation marks around the term) to double-check our work. When we clicked on "Go To Web Page Matches," thousands of results appeared. We tried the first link, a web page from York
University titled "Spatial Resolution (Visual Acuity)." The quoted research corroborated our earlier findings -- 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 closer to 20/10. If only all Ask Yahoo! answers were that clear...
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