Uses of concave lens

Concave lenses for eyeglasses

Concave lenses are most often used to correct nearsightedness. In myopic patients, the eye is too long for images of distant objects to fall on the retina. Therefore, concave lenses are used in eyeglasses to correct this deficiency by spreading the light before it reaches the eye. This allows a person to see distant objects more clearly.

 

Used in lasers

Different types of scanners, medical devices, CD and DVD players all use laser beams. Since laser beams are highly concentrated, they are spread out for the equipment to work properly. Small concave lenses are used to expand the laser beam to sharpen it into a specific area.

 

Used in cameras

To improve the quality of photographs, combinations of convex and concave lenses are widely used by camera manufacturers. When only a convex lens is used as the main lens of a camera, it causes distortion in the photo, which is called chromatic aberration. By combining concave and convex lenses, these undesirable effects can be eliminated.

 

Used in flashlights

Concave lenses are also used in flashlights to amplify the light produced by a light source. The light falls on the hollow side of the lens, while the light diverges on the other side. This increases the radius of the light source, thus providing a wider beam.

 

For peepholes

A peephole or door viewer is a security device that allows a panoramic view if there is an object outside the wall or door. A concave lens is used to minimize the scale of the object, giving a wider view of the object or area.