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20/20 is actually just normal vision, not perfect eyesight.
by Hamuko 5y ago
20/20 is actually just normal vision, not perfect eyesight.
- irrational 5y agoWhat is perfect vision? I thought 20/20 meant you don’t need glasses or any other aids to see. Would perfect vision being able to see everything in the electromagnetic spectrum? How big would one eyes need to be?
- schoen 5y agohttps://en.wikipedia.org/wiki/Visual_acuity#Expression https://en.wikipedia.org/wiki/Visual_acuity#Expression > Some birds of prey, such as hawks, are believed to have an acuity of around 20/2; in this respect, their vision is much better than human eyesight. The scale of how good vision can be keeps going and going indefinitely (presumably until you get into physical limitations to resolution related to wavelengths). While 20/20 is considered normal and not in need of correction, it doesn't mean it's the best vision observed among human beings, or the best that's physically possible (for human beings or other animals).
- thaumasiotes 5y ago> What is perfect vision? https://en.wikipedia.org/wiki/Superman#Powers,_abilities,_and_weaknesses https://en.wikipedia.org/wiki/Superman#Powers,_abilities,_an... > I thought 20/20 meant you don’t need glasses or any other aids to see. No, of course not. Try looking at Saturn at night. Then try looking through a telescope. Odds are you'll see it better with the aid.
- throwawayboise 5y agoYes, this just means you (first number) can see at 20 feet what the normal person (second number) can see at 20 feet. I don't know why 20 feet became the standard for comparison.