As the origins of life and the eye are ocean-based, it makes sense that the properties of the human eye ("why we see what we see") were largely evolved to perform specific tasks suitable for water. The fact that we can only observe a limited range of the electromagnetic spectrum—the part that water doesn't filter out—being a good example.

However, is the fact that we perceive water as being "clear" important? Is our optic system calibrated to see clean water as "clear". Obviously there are many things to factor in here: what the eye receives, how the brain perceives colour, even how we sociologically define colours, but water having "no colour" and not causing alarm or distress, for whatever reason would seem to be a good default for the whole thing.

Does anyone have any thoughts on this?

How do we know that I see red as you see red, or do we even know this at all? also how do we know the vision of other animals eg, if they see in coulour ect.

I have blue eyes and I squint in the light even if it is not a particuarly bright day. I often wear sun glasses when my brown eye friends are fine without. I got to thinking, does the colour of our eyes effect how sensitive they are to light in a similar way to how pale skin is more sensitive to sun light than dark skin?

What I mean is, when looking at a TV, the old ones not flat screens, I get light looking as though it is going out of the TV and upwards and also it is coming out of the bottom of the TV.

This also happens when looking at streetlights, kind of like the childrens drawings of the circular Sun and the rectangular beams of light stretching out.

Also, these 'beams' don't go on for too long, can't gauage the distance because it seems to be realative. The light also is the same colour as ones that are on the TV screen.

A lady was wearing a black and white striped cardigan, and from close up I could see the separate stripes clearly, but when she walked away and got to about 20 metres distance from me the colours seemed to fuse together and go grey.

I'm assuming this is because the gaps between the stripes became too small for my eyes to define them.

So is this an unrecognised evolutionary advantage (being able to watch television the way we do doesn't count) or simply a fault with our eyes?

Many thanks,

Lana

My physics teacher claims that a very good slr camera is better than the human eye.

However I can't believe this is true. His argument was: If you stare at a single word in the centre of a page of a book, you wont be able to read the first word, whereas if you took a photograph you would quite easily be able to see every word.

Furthermore, if anything really was better than the human eye, how on earth would we be able to tell that it is better?

When I'm walking home from work at night, in the suburb, I can see rainbows around the sodium street lamps. They are usually best seen from about 10 metres away, and the rainbow's about a metre or ttwo out from the street lamp.

I've asked my friends, but nno one else can see these... is it normal?

I know this might appear to be a rediculous question, but it seems a little odd that a creature with compound eyes on the sides of it's head would have to turn its face directly towards an object to see it. I know this is an action that's generally associated with predators, in order to focus on pray, but the eyes of a mantis have neither the structure nor position of say, those of a wolf or a cat. And I never see other insects doing this, predators or otherwise.

Also, exactly why is it that a praying mantis' eyes darken when deprived of light, when again this is not something (at least as far as I have seen, and believe me, I spent the better part of my life catching and observing insects) that appears to be common in insects.