Eyes are made of several different parts. The white part of the eye is called the sclera.(It is interesting to note that only in Human Species among all other creatures that sclera is visible when the eyes are open). This part covers the surface of the eyes except at the very front. At the front of an eye is a cornea. This part acts like a shield for the eye. It can still let light pass through because it is transparent. Under the cornea is the iris and pupil. The pupil is the black circle in the middle. It is actually a hole that lets light pass through into the back of the eye. The iris is a coloured diaphragm around the pupil. It is a muscle that opens and closes around the pupil to let more or less light through. Behind the pupil is a lens that focuses the light that passes through it onto the retina.

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