Optics/Lenses

See also wikipedia: List of many optics topics
 * Holding a magnifying glass against a wall at the proper distance usually will provide a picture of the lit-up parts of the room. Note that that distance varies, depending on the distance of the object concerned from the lens. Objects that are far away will require a distance called the focal length, while objects that are closer to the lens require a longer distance for a sharp picture of that object on the wall.
 * Eye glasses restore proper sight to very many people, also eyepieces of optical instruments include lenses.
 * Photography has many uses

Refraction at a spherical interface
See also wikipedia:Refraction

Locating the image
See also
 * Photography
 * Basics of the Camera
 * wikipedia:Camera

The lensmaker’s equation
See also
 * Optical Instruments
 * wikipedia:Lens
 * wikipedia:Photographic lens

Converging and diverging lenses
See also
 * wikipedia:Convex lens
 * wikipedia:Concave lens