Which defect of the eye can be corrected by using a cylindrical lens?
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A person cannot see distinctly objects kept beyond 2 m. This defect can be corrected by using a lens of power
(b) – 0.5 D. is the correct option.
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The focal length of the eye lens increases when eye muscles
(a) are relaxed and lens becomes thinner
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The human eye can focus objects at different distances by adjusting the focal length of the eye lens. This is due to
(b) Human eye can change the focal length of the eye lens to see the objects situated at various distances from the eye. This is possible due to the power...
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A doctor has prescribed a corrective lens of power + 1.5 D. Find the focal length of the lens. Is the prescribed lens diverging or converging?
Given P=+ 1.5D As P=1/f (in metre) , Focal length, f =1/P=1/1.5=0.667m=66.7cm As power of prescribed lens is positive, the lens is converging (or convex) lens.
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The human eye can focus objects at different distances by adjusting the focal length of the eye lens.
(b) accommodation.
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Some definitions are given below which can be corrected by changing one word. Correct them.
(a) change “above” with “below” (b) change “evaporation” with “seeping” (c) change “vapour” with “water”
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Write the importance of ciliary muscles in the human eye. Name the defect of vision that arises due to gradual weakening of the ciliary
Ciliary muscles adjust the curvature of the eye lens and change its focal length. Weakening of ciliary muscles leads to presbyopia. This can be corrected by a bifocal lens. (a) Akshay...
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The muscles of a normal eye are least strained when the eye is focused on an object (a) far away from the eye
(a) far away from the eye
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The distance of the eye-lens from the retina is x. For a normal eye, the maximum focal length of the eye-lens
The correct answer is (a) =x
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Astigmatism is corrected using (a) cylindrical lens
(a) Cylindrical lens is used to rectify eye defect astigmatism
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