Question

Question 10

Boojho while waving his hand very fast in front of his eyes, observes that his fingers appear blurred. What could be the reason for it?

Answer 1

The impression of an image persists for about 1/16th of a second on the retina. This is known as persistence of vision. If still images of a moving object are flashed on the eye at a rate faster than 16 per second, then the eye perceives this object as moving.
So, in a case by waving hand very fast in front of eyes the rate of movement of the hand becomes very large (much faster than 16 per second), therefore, the fingers appear blurred.