One of the instructors that I did my refresher with recently had a mask with changable lens covers. She wore the yellow one in the quarry we dove that day. I kinda wondered about adding more yellow to such greenish-brown water, but when someone asked her about them she said it gave everything more detail. That clicked with me because I'm into biology and my microscope came with several colored covers for the light -I use the yellow filter 95% of the time because it helps with detail. Now, that being said, I'm not going to run out and buy a yellow lensed mask. I dunno. I'd rather see everything as it is.
What herman said about the brain compensating for the color balance is interesting. It sounds similar to a well-known science experiment where you stare at a colored box on a piece of paper for 30 seconds, then look at a white wall. Between blinks you'll see the block in it's opposite color. -An old encyclopedia I had had a picture of Abe Lincoln in all kinds of blotches of odd colors. After staring at it, then looking at a white piece of paper, the image was in life-like colors. I thought it was pretty cool...
Anyway, it's just your brain being efficient and not recording data that seems to be static. It keeps getting a "red" signal from the rods and cones in your eyes, eventually it'll just assume that that's what the signal will continue to be, so it ignores the red signals until they change dramatically. I think this is what causes herman to see green after taking the mask off. It may have something to do with the brain compensating for color, but my hypothesis is a little different... In a clear mask, blue is over-saturated. So, our brains would begin to ignore it? Thus the natural color compensation? I don't know if this is true, 'cause I don't see red or orange when getting out of the water, but then, the blue usually decreases slowly as we come to the surface... Hmm... The science geek in me is intregued...
