$A$ person uses spectacles of power $+2D$. He is suffering from

If a human had only one eye,then:

$A$ person is suffering from a myopic defect. He is able to see clear objects placed at $15 \,cm$. What type and of what focal length of lens should he use to see clearly the objects placed $60 \,cm$ away?

For a normal eye,the cornea of the eye provides a converging power of $40\, D$ and the least converging power of the eye lens behind the cornea is $20\, D$. Using this information,the distance between the retina and the cornea-eye lens can be estimated to be ......... $cm$.

$A$ man can see only between $75 \, cm$ and $100 \, cm$. The power of the lens required to correct the near point will be:

Match the List-$I$ with the List-$II$ from the combinations shown:

$(I)$ Presbyopia	$(A)$ Sphero-cylindrical lens
$(II)$ Hypermetropia	$(B)$ Convex lens of proper power may be used close to the eye
$(III)$ Astigmatism	$(C)$ Concave lens of suitable focal length
$(IV)$ Myopia	$(D)$ Bifocal lens of suitable focal length