| aberration |
an imperfection in an optical lens, or the blurring caused by such an imperfection. [1/3 definitions] |
| anastigmatic |
free from astigmatism; esp. of compound lenses, being such that each part of the lens corrects the astigmatism in the other part. |
| aperture |
an opening, often adjustable, that controls the amount of light reaching the lens on a camera or other optical instrument. [1/2 definitions] |
| aqueous humor |
a clear, watery liquid that fills the chambers between the cornea and the lens of the eye. |
| astigmatism |
an irregularity in the curvature of a lens, including that of the eye, that prevents rays of light from meeting in a single focal point, resulting in an indistinct or distorted image. [1/2 definitions] |
| bayonet |
a pin protruding from an object such as a flashbulb or lens that secures that object to its socket. [1/3 definitions] |
| biconcave |
concave on both surfaces, as a lens. |
| biconvex |
convex on both surfaces, as a lens. |
| bifocal |
of eyeglasses or contact lenses, having two sections in each lens, one correcting for near vision and one for distant vision. [1/3 definitions] |
| camera |
a device with a shutter and lens that produces photographs by recording images on a light-sensitive film or plate. [1/2 definitions] |
| candid camera |
a small simple camera with a fast lens used to photograph unposed subjects or take informal pictures. |
| cataract |
clouding of the lens or capsule of the eye, blocking out light and causing partial or total loss of sight. [1/3 definitions] |
| concavo-convex |
pertaining to or designating a lens with a greater degree of curvature on its concave side than on its convex side. [1/2 definitions] |
| condenser |
a mirror, lens, or combination of lenses used to concentrate and direct light onto an object or area. [1/4 definitions] |
| contact lens |
a thin, usu. plastic lens, clear or tinted, that is worn over the cornea of the eye to correct imperfect vision or change the color of the eyes. |
| convexo-concave |
in optics, pertaining to a lens in which the convex side has a greater curvature than the concave side. (Cf. concavo-convex.) [1/2 definitions] |
| diopter |
a unit of measure of the refractive power of a lens, equal to the power of a lens with a one-meter focal length. |
| eye |
a mechanical or electronic device such as a camera lens that looks or functions like a biological eye. [1/9 definitions] |
| eyeglass |
a hand-held glass lens used to enhance vision; monocle. [1/4 definitions] |
| eyepiece |
the lens or lenses in an optical instrument, such as a microscope or telescope, through which one views the object or image under scrutiny. |
| fisheye lens |
a wide-angle camera lens that covers a full 180 degrees, producing images characterized by peripheral distortion and dramatically foreshortened perspective. |