External and internal eye anatomy. Overview. The cornea allows light to enter the eye. As light passes through the eye the iris changes shape by expanding and letting more light through or constricting and letting less light through to change pupil size. The lens then changes shape to allow the accurate focusing of light on the retina.
Eye Structures (Front and Side Views) The slight bulge in the sclera at the front of the eye is a clear, thin, dome-shaped tissue called the cornea. The cornea directs light rays into the eye and helps focus them on the retina. The pupil is the opening in the coloured part of the eye (iris). It allows light to pass to the lens.
The external parts of the eye work together to protect the eye and all of its internal structures. The upper and lower eyelids form a moist region around the eye, and protect the surface of the eye from injury, infection, and disease. The eyelids contain muscles that enable them to open and close around the eye, and are covered with skin.
Eye Anatomy Both Internal And External Views
