Question

A child sitting in a classroom is not able to read clearly the writing on the blackboard.

(a) Name type of defect from which his eye is suffering. 

(b) With the help of a ray diagram show how this defect can be remedied.

Answer 1

(a) Since the student is not able to read distinctly the words written on the blackboard the student is suffering from Myopia or nearsightedness.

A myopic eye has its far point nearer than infinity. It forms the image of a distant object in front of its retina. This defect of vision occurs when the eyeball slightly elongates from front to back.

(b) This defect of vision can be remedied by using the appropriate concave lens, the concave lens is the diverging lens, therefore, it does not form the image on the retina thereby curing the defect.

Figure below shows the myopic eye without concave lens and with concave lens.