Question

When a ray of light is directed towards the human skin(hand), it cannot be seen from the other side of the hand. But when a laser is directed it passes through the hand and can be seen on the other side. Why is it so?

Answer 1

This depend upon the wavelength of the light.
Visible light can can not pass through the human body but gamma rays can pass through human body because wavelength of gamma rays is less than the visible light.