Visual illusions, their causes, characteristics and applications (1922)
Luckiesh, Matthew, b. 1883 · New York, D. Van Nostrand company · leaf 86
EQUIVOCAL FIGURES 71 changed, thus producing momentarily a rather peculiar figure consisting of two solids, for example, attached by necessarily warped surfaces. Perhaps the reader has often witnessed the striking illusion of some portraits which were made of sub- … Fig. 35. — Thiery's figure. jects looking directly at the camera or painter. Re- gardless of the position of the observer the eyes of the portrait appear to be directed toward hun. In fact, as the observer moves, the eyes in the picture follow him so relentlessly as to provoke even a feeling of…
Optical illusions
Internet Archive · Cornell University Library · Public domain (published before 1931). Free to use for anything.
