(physics) The projection of a grid of lines onto a target in order to obtain information of its structure, typically by analysing the Fourier transform of the reflected light

A form of microscopy that employs structured illumination to observe biological structures smaller than the wavelength of the light used

An optical illusion in which the sides of a square placed inside a pattern of concentric circles take an apparent curved shape.

(phonetics) The state or condition of being illabial or unrounded.

Not labial; unrounded or unlabialized.

An optical illusion in which a white area takes on a pale tint of a thin, bright, intensely colored polygon surrounding it if the coloured polygon is itself surrounded by a thin, darker border.

An optical illusion where an edge between regions of the same shade causes them to be perceived as different shades.

(uncountable) Lightweight, mass-appeal theatrical productions such as pantomimes and musicals, as opposed to the "legitimate theater" of serious drama.

plural of illegitimate theater

(philosophy) An argument for the existence of sense-data, and thus a criticism of direct realism, according to which what we perceive (such as a stick that looks bent because it is viewed underwater) is distinct from the actual thing perceived (the straight stick).