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How come do we see neatly without correction under water? (lemmy.world)

submitted 1 week ago by BeatTakeshi@lemmy.world to c/asklemmy@lemmy.ml

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When snorkeling, scuba diving, or just swimming with goggles, you don't need corrective glass, why does water do this and not air? Both are transparent continuous fluids.

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[–] Ziggurat@jlai.lu 4 points 1 week ago

A factor may be that you don't see far in water, and details are big (think these black line at the bottom of the pool, not really hard to see)

Attenuation length is shallow water is relatively short, so even with googles and perfect distance vision, you won't see much behind 10-20m, and may-be 40-80m in deep water (bit there it's dark).

Mary glasses wearer still have a vision good enough to see decently at 10m especially when they don't look for ultra small details.