Question

Distinguish between:

Myopia - Presbyopia

Answer 1

	Myopia	Presbyopia
1.	This problem of vision arises due to slight elongation of eyeball or curved lens.	In this problem, the near point of aged people recedes. Also, ciliary muscles lose the capacity to change the focal length ofthe eye lens.
2.	In this defect, human eye can see nearby objects distinctly but unable to see distant objects clearly.	In this defect, aged people find it difficult to see nearby objects comfortably and clearly. Sometimes they are unable to see nearby as well as distant objects clearly.
3.	This defect can be corrected using concave lens of suitable focal length.	This defect can be corrected using bifocal lens in which concave lens is useful for distinct vision and convex lens is useful for near vision.