Question

What is the function of each of the following parts of an eye? a. Sclerotic, b. Choroid, c. Retina, d. Iris, e. Rods, f. Cones, g. Optic Nerve.

Answer 1

Step 1: Human Eye

1. The human eye is a light-sensitive organ that enables us to see. The construction and working of the human eye are similar to that of the photographic camera.
2. The human eye is almost like a spherical ball with a slight bulge in the front.
3. It has a diameter of about 2.3 cm.

Step 2: Functioning of each of the parts:

1. Sclerotic: It is the outermost covering of the eye. It consists of white fibrous tissue. It protects the vital internal parts of the eye.
2. Choroid: The dark pigmented membranous layer attached to the sclerotic on its inner side is called the choroid. It is richly supplied with blood vessels.
3. Retina: The innermost delicate membrane that has a large number of light-sensitive cells. These cells are called rods and cones. The retina of an eye locates where the image of an object forms.
4. Iris: Behind the cornea is an opaque diaphragm called the iris. It lends color to the eye. By adjusting the size of the pupil the iris controls the amount of light that enters the eye.
5. Rods: The rods are sensitive to the intensity of light.
6. Cones: The cones are sensitive to colors.
7. Optic nerve: There are about one million separate nerve fibers that carry the rods and cones signals of the retina to the brain. These one million separate nerve fibers make up the optic nerve.