Light that strikes an object can be reflected, absorbed or transmitted. Firstly a plane mirror produces an image that is upright and the same size as the object. A concave mirror can form either virtual images or real images. Images formed by convex mirrors are always virtual.
When light rays hit the surface of a medium at an angle, they bend or change directions. The type of image formed by a convex lens depends on the position of the object in relation to the focal point. Concave lenses produce only virtual images.
You see an object as the color of the light it reflects. The primary colors of light are red, green, blue. As pigments, found in paints and other things, are added together fewer colors of light are reflected and more are absorbed.
You see objects because of a series of steps that involve the structures of a series of steps that involve the structures of the eye and the brain. Lenses can correct some vision problems such as nearsightedness and farsightedness.