Question

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

1. The impression of an image does not fade instantly from our retina, but rather remains for $\frac{1}{16}th$ of a second.
2. If we move our hands faster than this, they will appear to be moving in a blur.
3. This is what is happening to Boojho, whose fingers are blurring as a result of his hand's rapid movement.
4. The persistence of vision is the cause of Boojho's blurred vision, which he notices while waving his hand in front of his eyes very quickly.