visual acuity
(Science: microscopy) The ability to detect fine details or small distances with the eye. Visual acuity can vary substantially depending on the definition used and method of measurement chosen. Under favourable conditions, the resolution of the human eye or ability to distinguish the twoness of adjoining lines, is about I minute of arc while the threshold delectability, or the detection of misaligned steps in a line (which is also a form of visual acuity), can be as low as a fraction of a second of arc.
Sharpness of vision; the visual ability to resolve fine detail (usually measured by a Snellen chart).
Dictionary > Visual acuity
