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Eye'sAnatomy

A summary

It is the outermost membrane of the eye. In addition to protecting the eye, it gives it its shape. In front of the eye, the sclera becomes transparent and bulges to form the cornea.

The cornea is the first transparent layer encountered by light rays, it is a part of the sclera in front of the eye. The shape of the cornea helps to transmit and converge light rays.

The iris is a colored disc with a hole. It regulates the amount of light that enters the eye through its opening, the pupil.

It controls the amount of light that enters the eye. In a dark environment it is larger (which allows as much light possible to pass through) and in a bright environment it is smaller (which helps prevent blindness from seeing too much light).

The cristalline is an elongated lens whose curvature is variable. It is held by muscles and helps to form a clear image on the retina.

This is where the optic nerves transform light rays into information for the brain. Indeed, it is the cones and the rods (name of those cells) that allow this transformation. The cones are specialized for detecting colors while the rods are specialized for detecting the intensity of light. The rods are rather useful for night vision, which explains the proverb: "At night all cats are gray", because indeed, they do not detect color.