Last modified on 24 September 2016, at 07:46

Lens

A lens is a sheet of glass or similar transparent material of tapering thickness, which refracts light in order to magnify. Lenses are used in cameras, telescopes and microscopes, as well as in spectacles. Contact lenses are lenses placed directly against the human eye as an alternative to spectacles. The eye itself contains a lens which is used to focus.