A concave lens is used in optical instruments. In other mentioned options, a concave lens is not used.
- A concave lens is used by the manufactures of binoculars and telescopes
- Opticians use concave lenses to correct near-sightedness also called myopia.
- Camera manufacturers use combinations of concave and convex lenses to improve the quality of photographs.
- Concave lenses are used on flashlights to magnify the light produced by the bulb.
- Lasers (CD, DVD players for example).