Question

An old person finds it difficult to see nearby objects comfortably and distinctly without corrective eye glasses.
1) list two causes for the development of this defect.
2)what kind of lens will be required to see clearly the nearby as well as distant object?give reason.
How is the eye defect of old person differing from near sightedness and far sightedness?

Answer 1

1) gradual weaking of ciliary muscles
diminishing flexibility of eye lens
2)use of convex lens of suitable power ,to correct near point

because it occurs the to ageing ( the power of accommodation if the usually decrease with ageing)