Sight is our most used sense contributing more than 75% of all knowledge that we learn throughout our lifetime. The eye is a small organ yet is capable of seeing objects, as tiny as a grain of sand, and as distant as a star. It allows us to focus on objects near and far, as well as distinguish between millions of colours. Actually, we don ‘t see objects, only the light they reflect which is interpreted as visual images.
Firstly, the cornea, which is responsible for the majority of the eyes focus, takes a wide spectrum of light which refracts or bends it through the pupil, the round opening in the centre of the iris. From the pupil the light travels through the lens where it is focused even more finely and directed to the retina. For details on Eye Anatomy please follow the link.