Can You Have 20/20 Vision and Still Need Glasses?
What is 20/20 Vision? 20/20 is a term that describes how small you can read and at what distance. It's equivalent to 6/6 in metric. 20/20 is the ability to read 20pt characters at 20 feet, and 6/6 is 6mm characters at 6 metres. They are also called Snellen fractions, named after Herman Snellen
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