Monday, 9 February 2009

Evolution and short-sightedness

Eyes I was told are part of the brain. Yucks – part of our thinking organ actually sticking out of our head! But our eyes are not perfect and many people are short-sighted (in the UK about five million). But why? What terrible thing have these people done to be cursed by the affliction of myopia – the inability to see clearly beyond one’s own nose?

Nowadays short-sightedness is no big deal. We can always wear spectacles - or contact lenses if we don’t mind poking our fingers into our eyes every day. And it’s even possible to have short-sightedness fixed by laser surgery. But this wasn’t the case back when we were hunter gathers and living in caves and wearing sheep pelts to keep ourselves warm. Back then short-sightedness would have meant death - cos how can you spear an animal if you can’t see it? And how can you recognize friend from foe if you can’t tell them apart?

So why then is short-sightedness so common? After all, it’s a very simple condition caused by a cornea which is simply a bit too curved. Is it too much to expect evolution to give us decent eyes? Well I don’t think so - cos there are far more complicated things in our biological makeup that nature doesn’t get wrong, so why can’t it give us a perfect cornea and decent eyesight?!!! Let’s fact it: when was the last time you saw a man with one hand bigger than the other?

Weird thing evolution, that’s for sure.

But short-sightedness doesn’t mean stupidity – possibly the opposite – and scientists now want to dig up Galileo’s body and do DNA tests on the eyes because they believe some of his errors were caused by “poor” eyesight. Now if that ain’t a myopic decision, I don’t know what is. What the hell is the point? Can’t they just let him rest in peace?

And even if you do have good eyes you have too be careful. What you see can be deceptive:

Our eyes are crap: these two tables are the same size, but it doesn’t look that way does it?!!!!!!