Question
Sat February 04, 2012 By:
 

can you please explain me the defects of vision. i could not understand what is the focal length of a defected eye of both the defects

Expert Reply
Mon February 06, 2012
The defects of the Eye: Myopia, Hypermetropia Myopia: Nearsightedness, also called myopia is common name for impaired vision in which a person sees near objects clearly while distant objects appear blurred. In such a defective eye, the image of a distant object is formed in front of the retina and not at the retina itself. Consequently, a nearsighted person cannot focus clearly on an object farther away than the far point for the defective eye. In this case, focal length of the eyes decreases. Hypermetropia: Farsightedness, also called hypermetropia, common name for a defect in vision in which a person sees near objects with blurred vision, while distant objects appear in sharp focus. In this case, the image is formed behind the retina. In this case, focal length of the eye lens increases a lot.
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