Question

Explain the structure of the human eye.

Answer 1

Eye:

1. The eyes are organs that allow you to see.
2. The eye is a sensory organ.
3. It collects light from the visible world around us and converts it into nerve impulses.
4. The optic nerve transmits these signals to the brain, which forms an image so thereby providing sight.

Structure of the eye: The external structure of the eyes are the sclera, conjunctiva, cornea, iris, and pupil. The internal structure includes lens, retina, optic nerve, aqueous humour, and vitreous humour.

1. Optic nerve: Located posteriorly in the eye and they basically carry nerve impulses from the eye to the brain for perception.
2. Retina: It is present as the innermost layer in the eye. It is a photosensitive layer and it converts the image into electrical nerve impulses for visual reception in the brain.
3. Sclera: It is made up of dense connective tissue and is the visible outer portion. It helps in the protection of the inner layer.
4. Conjunctiva: It lines the sclera. It keeps our eyes moist by secreting tears and mucus.
5. Cornea: It covers the iris and the pupil. The refraction of light is the main function.
6. Iris: It is the pigmented-colored portion that is visible externally. The main function is to adjust the size of the pupil.
7. Pupil: It acts like camera focus and allows light to enter. It gets focused on the retina.
8. Lens: It is the transparent, biconvex lens of an eye. The cornea along with the lens helps in the refraction of light.
9. Aqueous humour: It is present between the cornea and the lens. It is a watery fluid-like substance. It provides nourishment to the eye and keeps it inflated.
10. Vitreous humour: It is present between the lens and the retina. It is a transparent jelly-like substance. It also provides protection to the eye and maintains its spherical shape.