Reflection of light, the human eye, the mechanism behind human vision, sources of light, incidence of light rays on objects, reflection of light rays from objects, etc., are the topics dealt with in this module. How are we able to see the different objects around us? It is because light rays are incident on them, get reflected from the objects and then reach the eye. An inverted image of the object is then formed on the screen behind the human eye which is called the retina. The electrical impulses from the eye are transmitted to the brain by the optic nerve which is made of millions of nerve fibres. Finally the brain decodes the signals received and we are able to see an erect image of the object. If there is no source of light, there is no reflection, therefore no vision.