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

Convex and concave lenses can both be used to correct defects of vision. The most commonly occurring defects of vision are ‘short sightedness’ and ‘long sightedness’. People who are ...

The two types of concave lenses — biconcave and plano-concave — are negative. Meniscus lenses — a third broad type also referred to as convex-concave — can be either positive or negative, depending on ...

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 ...