apparent visual angle

apparent visual angle

[ə′pa·rənt ′vizh·ə·wəl ′aŋ·gəl]
(optics)
The angle subtended by a source at the observer's eye as calculated from the source size and distance from the eye.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.