Question

No image formation occurs on blind-spot of retina because

• A. It is not present of the optical axis of the eye.
• B. Here, cones and rods are absent.
• C. On this part, only cones are present.
• D. The nerve fibres of this region do not contribute in the formation of optic chiasma.

Answer 1

The correct option is B Here, cones and rods are absent.

The blind spot is a small portion of the visual field of each eye that corresponds to the position of the optic disk within the retina. There are no photoreceptors (i.e., rods or cones) in the optic disk, and, therefore, there is no image detection in this area. The blind spot of the right eye is located to the right of the centre of vision and vice versa in the left eye. With both eyes open, the blind spots are not perceived, because the visual fields of the two eyes overlap.