A student sitting at the backbench in a class has difficulty in reading. What could be his defect of vision? Draw ray diagrams to illustrate the image formation of the blackboard when he is seated at the (i) back seat (ii) front seat. State two possible causes of this defect. Explain the method of correcting this defect with the help of a ray diagram.

A student find the writing on the blackboard as blurred and unclear when sitting on the last desk in the classroom. He, however, sees it clearly when sitting on the front desk at an approximate distance of 2m from the blackboard. Draw ray diagrams to illustrate the formation of image of the blackboard writing by his eye-lens when he is seated at the (i) last desk (ii) front desk. Name of the kind of lens that would help him to see clearly even when he is seated at the last desk. Draw a ray diagram to illustrate how this lens helps from to see clearly.

A student sitting at the back of the classroom cannot read clearly the letters written on the blackward. What advice will a doctor give to her ? Draw ray diagram for the correction of this defect.

Draw ray diagrams to illustrate the formation of a virtual image by using (i) a convex lens, and (ii) a concave lens. (b) What is the difference between the two images formed above?

A student has difficulty reading the blackboard while sitting in the last row. What could be the defect the child is suffering from? How can it be corrected?

A student finds the writing on the blackboard to be blurred and unclear when he sits beyond the front row at an approximate distance of 2 m from the black board. Draw ray diagram to illustrate the formation of image of the writing on the blackboard by his eye lens when he is seated in the front row

A student finds the writing on the blackboard to be blurred and unclear when he sits beyond the front row at an approximate distance of 2 m from the black board. Draw ray diagram to illustrate the formation of image of the writing on the blackboard by his eye lens when he is seated in the last row

(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?