The aim of this lecture is to present on Convex Lenses. A convex lens is a diverging lens. When parallel rays of light pass through a concave lens the refracted rays diverge so that they appear to come from one point called the principal focus. Rays traveling parallel to the principal axis of a convex lens will refract toward the focus. Rays traveling from the focus will refract parallel to the principal axis. Rays traveling directly through the center of a convex lens will leave the lens traveling in the exact same direction.