The light when enters the human eye experiences most of the refraction while passing through

Your friend is having an eyesight problem. She is not able to see a distant uniform window mesh clearly,and it appears to her as non-uniform and distorted. The doctor diagnosed the problem as:

Myopia is due to

The far point of a myopic person is $80\, cm$ in front of the eye. What is the power of the lens required to enable him to see very distant objects clearly?

The least distance of distinct vision of a long-sighted person is $60 \ cm$. By using a spectacle lens, this distance is reduced to $12 \ cm$. The power of the lens is

The near point and far point of a person are $40\,cm$ and $250\,cm$ respectively. Determine the power of the lens he/she should use while reading a book kept at a distance of $25\,cm$ from the eye $..........D$