GK
HUMAN BODY AND REPRODUCTION
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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Bifocal Lens
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Convex lens
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Concave lens
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Convex mirror
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Detailed explanation-1: -In this defect focal length or radii of curvature of the lens is reduced or the power of lens increases or distance between eye lens and retina increases i.e., eyeball becomes too long. This defect can be removed by using a concave lens of suitable focal length. Therefore option 2 is correct.
Detailed explanation-2: -Concave lenses are the type used for treating shortsightedness and they work by bending the light rays slightly outwards so that they can focus further back on the retina.
Detailed explanation-3: -You know that myopia is a common refractive defects of vision. A person with this defect can clearly see only objects that are near. Using concave lens of suitable power this defect is corrected.
Detailed explanation-4: -Concave lenses are used to treat myopia (Fig.