Why do you go blind if you're in darkness for too long?

Question

Ya 'll heard of ppl getting lost in caves in complete darkness for (?a while, I guess, cause if they're not found they'd die, but thats besides the point?) too long apparently and becoming blind, why?

Answer 1

Like any organ or muscle, if you do not use it enough, it will atrophy. It will cease to function because it does not need to function and get to the point where it cannot be "healed" or regenerated.

Answer 2

First of all, seeing things, or reading in the dark is not the culprit. Most scientists can't even agree on whether or not prolonged exposure to darkness can ruin your vision, and in fact some studies have shown that reading in well lit areas can cause strain. Regardless, I don't see anyone going blind by being in the dark for a long time. Like walking outside on a sunny day, your eyes may take a while to get used to a change in the light, which may cause temporary blindness, or, since your dialated pupils may not be ready for so much light, the exit from the cave may cause the damage itself.

Some species of animals that live in dark places are blind because their eyes have, through evolution, been disused, though this is quite different.

Answer 3

I've never heard of someone biend permanetly blind from something like that. I suppose your eyes would just get used to not seeing light and start to break down. Either that, or the strain of trying to focus in on the small amounts of light that are there weaken the eyes.

Answer 4

Ur wrong this cant happen if u have compared us with bats thats a different track.By evolution nyctilopic animals have only rod cells in their retina so they r colourblind but can see in darkness but we have 12crore rods and 70 lac cones so we can see colour and also to a little extent at night