Draw a ray from the object to the lens that is parallel to the principal axis. Once through the lens, the ray should pass through the principal focus. Draw a ray which passes from the object ...

A plano-concave lens is a lens with one side being flat and the other side being concave. It is characterized by being thin in the center and thick at the edges, and can make parallel light rays ...

Two common defects of the eyes are myopia (short-sightedness) and hyperopia (long-sightedness). In both cases, rays of light do not focus on the retina so a clear image is not formed. These two ...