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class 10th science
Answers
Cornea: The front transparent part of the sclera is called cornea. Light enters the eye through the cornea.
Iris: A dark muscular tissue and ring like structure behind the cornea are known as the iris. The color of iris actually indicates the color of the eye. The iris also helps regulate or adjust exposure by adjusting the iris.
Lens: Behind the pupil, there is a transparent structure called a lens. By the action of ciliary muscles, it changes its shape to focus light on the retina. It becomes thinner to focus distant objects and becomes thicker to focus nearby objects
ciliary muscles they changes the focal length of the lens by contracting and expanding
as it contracts the focal length of the lens decreases and as the muscles expand the focal length increases.
hope it helps you...
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.
Iris forms the coloured part of the eye. It adjusts the size of the pupil, thereby controls the amount of light entering the eye.
the crystalline lens, lies behind Iris 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.
Pupil controls the amount of light entering the eye
Ciliary muscle helps in adjusting the focal length of the lens by contraction or relaxing