VISUAL ILLUSIONS
THEIR CAUSES, CHARACTERISTICS
AND APPLICATIONS
BY
M. LUCKIESH
DIRECTOR OF APPLIED SCIENCE, NELA RESEARCH LABORATORIES,
NATIONAL LAMP WORKS OF GENERAL ELECTRIC CO.
AUTHOR OF “COLOR AND ITS APPLICATIONS,” “LIGHT AND SHADE
AND THEIR APPLICATIONS,” “THE LIGHTING ART,” “THE
LANGUAGE OF COLOR,” “ARTIFICIAL LIGHT—ITS
INFLUENCE UPON CIVILIZATION,”
“LIGHTING THE HOME,” ETC.
100 ILLUSTRATIONS
NEW YORK
D. VAN NOSTRAND COMPANY
EIGHT WARREN STREET
1922
Copyright, 1922, by
D. VAN NOSTRAND COMPANY
PREFACE
Eventually one of the results of application to the analysis andmeasurement of the phenomena of light, color, lighting, and vision is afirmly entrenched conviction of the inadequacy of physical measurements asa means for representing what is perceived. Physical measurements havesupplied much of the foundation of knowledge and it is not a reflectionupon their great usefulness to state that often they differ from theresults of intellectual appraisal through the visual sense. In otherwords, there are numberless so-called visual illusions which must be takeninto account. All are of interest; many can be utilized; and some must besuppressed.
Scientific literature yields a great many valuable discussions fromtheoretical and experimental viewpoints but much of the material iscontroversial. The practical aspects of visual illusions have been quitegenerally passed by and, inasmuch as there does not appear to be a volumeavailable which treats the subject in a condensed manner but with a broadscope, this small volume is contributed toward filling the gap.
The extreme complexity of the subject is recognized, but an attempt towardsimplicity of treatment has been made by confining the discussion chieflyto static visual illusions, by suppressing minor details, and by[Pg iv]subordinating theory. In other words, the intent has been to emphasizeexperimental facts. Even these are so numerous that only the merestglimpses of various aspects can be given in order to limit the text to asmall volume. Some theoretical aspects of the subject are still extremelycontroversial, so they are introduced only occasionally and then chieflyfor the purpose of illustrating the complexities and the trends ofattempted explanations. Space does not even admit many qualificationswhich may be necessary in order to escape criticism entirely.
The visual illusions discussed are chiefly of the static type, although afew others have been introduced. Some of the latter border upon motion,others upon hallucinations, and still others produced by external opticalmedia are illusions only by extension of the term. These exceptions areincluded for the purpose of providing glimpses into the borderlands.
It is hoped that this condensed discussion, which is ambitious only inscope, will be of interest to the general reader, to painters, decorators,and architects, to lighting experts, and to all interested in light,color, and vision. It is an essential supplement to certain previousworks.
...