Eye Anatomy

The cornea is a transparent layer that covers the front of your eye.

The retina is the inside layer on the back of your eye. It contains cells that are sensitive to light; they trigger impulses that help your brain determine what your eyes are seeing.

The lens is a clear, curved disc that focuses light rays onto your retina.

The pupil is a hole in the center of your iris that allows light flow into your eye.

The iris is a thin, circular structure that is responsible for controlling the diameter and size of your pupil.  This allows more or less light to reach the retina.