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A unit of brightness equal to 0.1 millilambert.
[G. apo, from + stilbē, lamp]
Farlex Partner Medical Dictionary © Farlex 2012
apostilbAn obsolete, non-SI (International System) unit of light, defined as the amount of light emitted from a diffusing surface corresponding to 1.0 lumen/m2.
Segen's Medical Dictionary. © 2012 Farlex, Inc. All rights reserved.
The luminance of a perfectly diffusing surface that reflects 1 lumen per square metre. This measure is often used in visual field analysis, where the luminance of the background and targets is measured in apostilb.
Millodot: Dictionary of Optometry and Visual Science, 7th edition. © 2009 Butterworth-Heinemann