In a ray diagram, a concave lens is drawn as a vertical line with inward facing arrows to indicate the shape of the lens.

Meniscus lenses have one convex and one concave surface with each surface having its own radius or curvature. Applications include lasers and cameras. There are two types of meniscus lenses. Positive ...

Draw a ray which passes from the object through the centre of the lens. Some ray diagrams may also show a third ray. Peep holes contain concave lenses. They are set into doors so the occupant can ...