NCERT Class XII Chapter
Ray Optics and Optical Instruments
Questions With Solutions
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Question : 25
Total: 38
Does short-sightedness (myopia) or long-sightedness (hypermetropia) imply necessarily that the eye has partially lost its ability of accommodation? If not, what might cause these defects of vision?
Solution:
A person with normal ability of accommodation may be myopic or hypermetropic due to defective eye structure. When the eye ball from front to back gets too elongated the myopic defect occur, similarly when the eye ball from front to back gets too shortened the hypermetropia defect occur.
When the eye ball has normal length but the eyelens loses partially its ability of accommodation, the defect is called “presbyopia” and is corrected in the same manner as myopia or hypermetropia.
When the eye ball has normal length but the eyelens loses partially its ability of accommodation, the defect is called “presbyopia” and is corrected in the same manner as myopia or hypermetropia.
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