Physical Science:

Light is a form of energy. It excites the sensation of vision when strikes the eye retina. To see things around having only eye is not very important but also the presence of light is very important. A blind person can not see anything even if the room is full of light just as a normal person can not see anything if room is completely dark. Light coming from an object when falls on the surface of eye retina we can see that object. Even though light helps us see things around light itself is invisible. However, we divide light into two categories, the visible light and the invisible light. It is not because we can or can not see the light rather it is based on the sensation of vision produced by these light in our eye. Light which can help sensation of vision is called a visible light and that which can not stimulate the sensation of vision is called an invisble light. Light is an electromagnetic radiation which consists of the ranges of waves from gamma rays to radio waves. The so called visible light is a very small portion of an electromagnetic radiation.