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Originally Posted by Cariabu Can someone please explain to me what 20/20 means or 20/30, 20/15 etc. I'm not sure I fully understand what the numbers represent? I've just always heard that 20/20 is perfect vision and I've always known I obviously don't have it. Please explain what it means in reference to one eye or 2 eyes and how you can tell what you are by viewing a eye Dr.'s chart etc.
Thank you,
Cari  |
20/20 is what as known as perfect vision and the vision chairt is based on feet from object. When getting an eye exam you stand behind a line which is 10' to 20' in length. WHen you have 20/20 vision it means you can read a sentence from 20 feet away and therfore have 20/20 vision (with both eyes). If you have 20/40 vision, it means that when you stand 20 feet away from the chart you can see what a normal human can see when standing 40 feet from the chart. That is, if there is a normal person standing 40 feet away from the chart and you are standing only 20 feet away from it, you and the normal person can see the same detail.
20/100 means that when you stand 20 feet from the chart you can see what a normal person standing 100 feet away can see. 20/200 is the cutoff for legal blindness in the United States. The higher the number the worse your eyes are
You can also have vision that is better than the norm. A person with 20/10 vision can see at 20 feet what a normal person can see when standing 10 feet away from the chart.
Hope that helps...and yes I stayed at a holiday inn last night.
What does 20/20 or 20/30 etc. mean? 
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