Optics and the human eye
I bought myself an optics kit as a Christmas present. It is awesome because it has lots of lenses, mirrors and lasers. I have been learning lots with it and I will be posting a few blog posts about this topic. I don't to spoil it but I will show you how to build your own telescope. But for today I will teach you what I have learnt about the human eye. There are two things that control the amount of light that enters your eye: the eye lids and the iris. I don't need to explain you what the eye lids are, because I think you already know. The other one is the iris which is the coloured part of your eye. One thing I learnt about it is that the pupil is just a hole in the iris, that gets bigger or smaller to let in the right amount of light. So it is not a thing by itself, it is just a hole in the iris. It is black because it is very dark inside. A curiosity of mine is that every human's iris is different, which is why it can be used for recognition. Then, there are two parts o...