The eye is made of three layers;
1/. Sclera [outer layer] -tough layer covering the eye thus protect and maintain its shape . to the front is the cornea which is transparent to allow light to pass through and be refracted as they get into the eye. The conjuctiva covers the cornea and protects it.
2/. Choroid [middle layer]- absorbs stay light rays. Has many blood vessels that provide nourishment to the eye. To the front ,it forms ciliary body and iris. The iris is thin round sheet of muscular tissue. it has two muscles,circular and radial which control diameter of pupil thus regulating amount of light entering the eye.
lens is transparent to allow light rays to pass through and refract it. It divides the eye into anterior and posterior chambers. Anterior part is watery fluid the aqueous humour while posterior part is jelly like substance called vitreous humour. Both are transparent to allow light to pass and refract them.They also maintain shape of the eye ball.
3/. Retina- is the innermost layer containing the light sensitive photoreceptors i.e cones and rods. Images are formed at the fovea centralis where a high concentration of the cones and rods are found.
