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?
Since the student is unable is unable to see faraway object, he is suffering from myopia.
In Myopia, the person is unable to see far away objects clearly but can see near objects clearly.
This defect of vision can be corrected by using spectacles having a concave lens of appropriate power