oculare

Ocuale, or more commonly oculare in some languages, is a term derived from the Latin oculus meaning eye. In English-language technical usage, the standard adjective is ocular and the standard noun for an optical eyepiece is eyepiece or telescope/microscope eyepiece; oculare appears mainly as a loanword or in historical/foreign-language contexts. The term is used across disciplines to indicate a relation to the eye or to a component designed for viewing with the eye.

In optics, oculaire refers specifically to the eyepiece of a device such as a microscope or telescope. The eyepiece is the part through which the observer looks; it often contains one or more lenses that magnify the image formed by the objective lens. Eyepieces can be fixed in magnification or interchangeable, and their design affects magnification, field of view, and eye relief.

In medical and anatomical contexts, the root oculus yields the English term ocular, which is widely used to describe structures, functions, and diseases of the eye, such as ocular muscles, ocular health, or ocular motility. The form oculare is less common in modern English but may appear in translations, multilingual glossaries, or as a direct loan from languages where the term is standard for eyepieces or eye-related terminology.

See also: ocular, oculus, eyepiece.