question_answer

Shyam views a certain object and finds that it is not properly visible to him. The image of the said object is formed by his eye lens 3 cm away from the pupil of his eye.Shyam can correct the defect in his vision by using

A)  convex lens   

B)  bifocal lens

C)  concave lens   

D)  cylindrical lens

Correct Answer: A

Solution :

  The diameter of the eye ball is approximately 2.3 cm. Images are formed on the retina of the normal eye, which is approximately 2.3 cm behind the pupil. The formation of an image 3 cm away from the pupil of the eye indicates that the light rays are focused behind the retina. For proper visibility, the light rays must focus on the retina. It can be concluded that Shyam is suffering from hypermetropia and a convex lens can be used to correct this defect. The correct answer is A.