A child while playing with his father's spectacles, burnt a hole in a piece of tissue paper by focussing the image of the sun on the paper.
(a) Name the defect of vision his father is suffering from.
(b) List two causes of the defect.
( c) Draw a ray diagram to show this defect may be corrected using a suiable lens.

(a) A student cannot see clearly a chart hanging on a wall placed at a distance of 3m from his eyes. Name the defect of vision he is suffering from. Draw a ray diagram to illustrate this defect. List its two possible causes. (b) Draw a ray diagram to show how this defect may be corrected using a lens of appropriate focal length. (c) What do you mean by the 'Power of Accommodation' of human eye?

Aniket from Std. X uses spectacles. The power of the lenses in his spectacles is -0.5 D. name the defect of vision Aniket is suffering from.

Nooper needs a lens of power - 4.5 D for correction of her vision. (a) What kind of defect in vision is she suffering from ? (b) What is the focal length and nature of corrective lens ? (c) Draw ray diagrams showing the defected eye and correction for the defect. (d) What are the causes of this defect ?

A person is unable to see objects distinctly placed within 50 cm from his eyes. (a) Name the defect of vision the person is suffering from and list its two possible causes. (b) Draw ray diagram to show the defect in the above case. (c) Mention the type of lens used by him for the correction of the defect and calculate its power. Assume that the near point for the normal eye is 25 cm. (d) Draw a labelled diagram for the correction of the defect in the above case.

Noopur needs a lens of power-4.5 D for correction of her vision. Draw ray diagrams showing the (a) defected eye and (b) correction for this defect.