Class X The Human Eye

Eye is the most important organ of our body. It consists of a tough fibrous membrane called sclera that protects the internal parts of the eye. Cornea is the membrane covering the front of the eye that is bulged out and is responsible for the maximum refraction of the light that enters the eye. Behind it lies aqueous humour that enables the eye to cope up with the atmospheric changes. Iris forms the coloured part of the eye. It adjusts the size of the pupil, thereby controls the amount of light entering the eye. Behind it lies the crystalline lens, a biconvex structure that helps in fine adjustment to the refracted light so that it is focused on the screen of the eye, which is referred to as retina. Ciliary muscle helps in adjusting the focal length of the lens by contraction or relaxing. Behind the lens lies vitreous humour which is a dense, clear, jelly like fluid which helps to maintain the shape of the eye and focus the image clearly on the retina.