a case of leather or other material in which spectacles are kept when not in use.

(See quot. 1753.)

Filters made of tinted glass, fitted to telescopes and other optical instruments to reduce the intensity of the sun's rays. Also in singular; = su…

In the manufacture of lenses and specula: a concave implement of metal or glass used in shaping the grinding tools or in smoothing fine abrasives…

a bed of whetstones used for grinding lenses or mirrors.

an apparatus consisting of one or more convex lenses which projects the image of a contrasting object onto a plumb line, or projects the image of the…

A device (typically a screen or tube) used with a telescope or other optical instrument to reduce the intensity of sunlight.

a bench to which optical instruments may be fixed; = optical bench n.

An instrument for measuring the refractive properties of ophthalmic lenses or of the lens of the eye.

a bench to which optical instruments may be fixed, typically using mounts which can be moved in order to provide different configurations and…

In full optical flat. A block or lamina (usually of glass) with one or more surfaces made accurately plane and smooth, any unevenness or departure…

a kind of soft, thin, absorbent paper suitable for wiping lenses.

(a) a cylinder or strip of (usually transparent) material along which visible, infrared, or ultraviolet light can travel with little energy loss by…

= lens paper n.

a transparent fibre used to carry light signals with very little loss, by means of total internal reflection.