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Attempt either (a) or (b) :
(a) How does the focal length of eye lens change as the distance of the object from the eyes is altered ? Explain.
(a) How does the focal length of eye lens change as the distance of the object from the eyes is altered ? Explain.
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(a)
* If the distance of the object from the eye is increased, ciliary muscles relax, lens becomes thin and so the focal length increases (1 Mark)
* If the distance between the object from the eye is decreased, the ciliary muscles contract, lens becomes thick and so the focal length decreases. (1 Mark)
OR
(b) In myopic eye image is formed in front of the retina. A concave lens / diverging lens of suitable power will bring the image back on to the retina. (2 Marks)
* If the distance of the object from the eye is increased, ciliary muscles relax, lens becomes thin and so the focal length increases (1 Mark)
* If the distance between the object from the eye is decreased, the ciliary muscles contract, lens becomes thick and so the focal length decreases. (1 Mark)
OR
(b) In myopic eye image is formed in front of the retina. A concave lens / diverging lens of suitable power will bring the image back on to the retina. (2 Marks)