A myopia person has been using spectacles of power `- 1.0` dioptre for distant vision. During old age, he also needs to use separate reading glasses of power `+ 2.0` dioptre. Explain what may have happened.

A myopic person has been using spectacles of power -1.0 dioptre for distant vision. During old age he also needs to use separate reading glass of power +0.2 dioptres. Explain what may have happened.

A myopic person has been using spectacles of power -1.0 dioptre for distance vision. During old age he also needs to use separate reading glass of power +2.0 dioptres. Explain what may have happened.

A myopic person has been using spectacles of power -1.0D for distant vision. During old age he also needs to use separate reading glass of power +2.0 dioptres. Explain what may have happened.

A myopic person is using spectacles of power -1.5 D for distant vision. How far can he see distincltly without specs ?

A person uses spectacles of power +2D. What type of defect of vision is it?

A person needs a lens of power - 5.5 dioptres for correcting his distant vision. For correcting his near vision he needs a lens of power +1.5 dioptres. What is the focal length of the lens required for correcting (1) distant vision and (2) near vision ?