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VISION SCIENCE
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Some Aspects of the Basis of Stereoscopic Vision
Kenneth N. Ogle
1953
This report discusses whether simultaneity is a factor associated with
disparity between the images in the two eyes and is necessary for the
emergence of the stereoscopic experience. It is well known that stereop-
sis can be obtained from disparate afterimages that are induced in each
eye separately. Experiments show, however, that stereoscopic depth from
afterimages is experienced only as long as the disparate retinal elements
involved are in an excited state at the same time.
Simultaneity with respect to retinal location concerns the question
whether the disparate stimuli, at least in part, must fall on specific horizon-
tally associated disparate retinal elements. In 1873, van der Meulen and van
Dooremaal reported their observations that bear on this question. They
used the Hering "falling sphere" test. In this test, through a horizontal
slit-aperture, the subject views a vertical thread (plumb line) as a fixation
object and judges whether a small sphere dropped by an assistant appears
to fall in front of or behind the fixed plumb line. A prism was placed base
down before one eye so that the image of the slit to the eye would be
seen entirely above the actual slit seen by the other eye. The images of
the plumb line would be uninfluenced and would appear just the same as
before. A small sphere now dropped near the plumb tide would not be
seen simultaneously by the two eyes. The upper half of the path of the fall
would be seen by one eye, the lower half of the path would be seen by the
other eye.
It was reported that the path of the falling sphere nevertheless could
always be correctly judged nearer or farther than the plumb line. These
authors concluded that stereoscopic depth is not to be conceived as a direct
physiological phenomenon but as a psychical one, that is, the depth is
produced by a psychophysical process. In this experiment, the stereoscopic
vision arises solely through the means of imagined prolongations of the half-
images, which then in the usual stereoscopic manner would be referred to
horizontally disparate retinal points.
6 pp. no figures no tables 6 references
Availabiliy: Committee on Vision, 2101 Constitution Ave., N.W., Wash-
ington, D.C. 20418.
81
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An Annotated Bibliography of Flicker-Fusion
Phenomena: Covering the Period 1740-1952
Carney Landis
1953
In 1948, evaluation of the experimental findings of the Columbia-
Greystone Brain Research Project suggested that the critical flicker-fusion
threshold was probably lowered as a result of surgical ablation of portions
of the human frontal lobes. A search for information in textbooks, hand-
books, and monographs dealing with the physiological psychology of vision
nowhere provided either an explanation of the observation nor indeed a
comprehensive treatment of the flicker-fusion phenomena. It became ap-
parent that many investigations had been made of flicker-fusion phenomena
but there was no comprehensive theory or review of the topic.
Flicker-fusion phenomena have been investigated by one or more
persons working in various disciplines, e.g., physics, chemistry, mathemat-
ics, physiology, zoology, botany, neurology, ophthalmology, optometry, as-
tronomy, anatomy, pathology, internal medicine, endocrinology, nutrition,
pharmacology, biology, biophysics, biochemistry, electrical engineering, il-
luminating engineering, and psychology. Flicker-fusion phenomena have
been discussed under titles such as: persistence of vision, photopic versus
scotopic vision, visual beats, visual ripple, intermittent vision, and duration
of retinal impressions. They have been studied in many states of physical
and mental pathology. The effect of a wide variety of drugs, chemicals,
hormones, and the like on flicker-fusion phenomena has been reported.
Yet, despite the fact that it has entered into such a wide variety of inves-
tigations, there is no comprehensive theory of flicker. The general theory
of Plateau (1834) is as complete as that of any of his successors. Marbe,
V. Kries, Sherrington, McDougall, Ives, Hecht, Crazier, and Ross have
theorized, but in each instance in a limited fashion that encompassed only
part of the available factual evidence. Even such a simple point as whether
the flicker-fusion threshold is dependent on retinal functional limitations
or on limitations imposed by the central nervous system has never been
clearly answered.
130 pp. no figures no tables 1,300 annotated entries (2,000 references)
Availability: National Technical Information Sentence ~S), 5285 Port
Royal Road, Springfield, VA 22161.
82
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The Measurement of Visual Function
Milton ~ Whitcomb and William Benson, Editors
1965
The purpose of this report is to provide a basis for reevaluating the
testing procedures for each of the different visual parameters useful in visual
classifications. A working group of the Committee on Vision reevaluated
some of the aspects of the visual requirements for flying and made some
general conclusions and recommendations regarding visual requirements,
visual standards for performance tasks in general, and the role of the visual
scientists in assessing visual capabilities and in assisting the agencies and
services with their needs for visual classification systems.
The laboratory methods of assessing each visual function are presented
in order to update the awareness of all possible testing techniques available
in assessing the considered visual parameter. The clinical presentations
are directed toward assessing those techniques best suited for practical
utilization in measuring the considered visual parameter by (a) professional
personnel, (b) nonprofessional (technical) personnel, and (c) machine or
semiautomated methods. Special reference is made to updating techniques
such as the utilization of electrodes, machines (orthorator types), and other
semiautomated techniques capable of quantifying or scaling the test scores.
Where appropriate, comments are made relative to training of the visual
function and predictability of change with age.
The material presented provides a basis for making judgments relative
to the preferred testing techniques best suited for the needs of the different
agencies and services requiring visual classification and testing. These
conclusions are derived from, or compared with, the array of laboratory
techniques available. The concern is with the testing techniques most
suitable for scoring and classification.
The papers presented in this volume are concerned with ideal and
practical techniques for the measurement of each of the selected visual
functions and cover the following topics: visual acuity; refractive error;
color vision; distance vision; phoria and ocular rotation; accommodative
amplitude; night vision; visual fields; intraocular tension; stress tolerance;
and clinical and laboratory measurement of visual functions (other than
those mentioned).
260 pp. 89 figures 4 tables 361 references
Availabiluy: National Technical Information Service (NTIS), 5285 Port
Royal Road, Springfield, VA 22161.
83
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Eye Movements and Psychological Processes
Richard ~ Montr and John W. Senders, Editors
1976
This volume brings together scientists from such disciplines as neurol-
ogy, physiology, engineering, medicine, and psychology to examine many
aspects of eye movement. It begins with an examination of the physiology
of eye movement control and then examines the role of eye movements in
vision, methods of recording eye movements, the relation of eye movements
to the perception of motion, position, and kinds of visual stimuli. Specific
fields such as target detection, search and scanning, reading behavior, and
highest cognitive processes are examined.
550 pp. 22 figures 21 tables 497 references
Availabilz~y: Lawrence Erlbaum Associates, Hillsdale, N.J.
84
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Electrophysiological Techniques in Vision
1977
This volume, the proceedings of a 1975 symposium, includes papers
presented at the symposium on five major topics relevent to electrophysi-
ological techniques for studying human visual functions. First, a historical
overview provides a brief description and appraisal of the techniques that
have been developed for stimulating and recording the visual responses
of the human eye and brain. Second, psychophysical applications of hu-
man electroretinography are given: rapid developments in human elec-
troretinography during recent decades have greatly increased its value for
investigating psychophysical problems. This review of the current status
of electroretinography considers the response waveform, recording tech-
niques, and data analysis. Several examples of electroretinal data that have
psychophysical significance are presented. Third, transient visually evoked
potentials are discussed. Fourth, steady-state evoked potentials are treated.
Finally, spatiotemporal mapping of scalp potentials are covered.
43 pp. 84 figures no tables 154 references
Availability: The Journal of the Opacal Society of America Vol. 67, No. 11,
pp. 1451-1494, 1977.
85
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Effects of Microwave Radiation on the Lens of the Eye
1981
A working group of the Committee on Vision was formed in response
to concern expressed by representatives of several federal agencies about
workers who may be exposed to microwave radiation. The committee was
requested to review the scientific literature concerning ocular effects of
microwave radiation and to comment on the adequacy of existing studies,
particularly in regard to the potential for ocular damage from microwave
exposure below the current standard. The Department of the Air Force
also requested comment on the desirability of routine screening for ocular
changes in all its personnel working around microwave devices.
Potential hazards of human exposure to microwave radiation are of
considerable concern because large numbers of people in the military ser-
vices and in industry work in the vicinity of microwave generators and also
because people may be exposed to radiation from devices such as microwave
ovens and diathermy devices used in physical therapy. Cataractogenesis is
the most clearly documented irreversible effect of overexposure to mi-
crowave radiation, but the mechanisms underlying this effect are poorly
understood.
The current standard for maximum permissible occupational exposure
to microwave radiation, recommended by the American National Stan-
dards Institutes (ANSI), is lOmW/cm2. This report surveys existing studies
of cataract induction by microwave radiation exposure and discusses the im-
plications of this literature for human exposure at levels below l()mW/cm2.
The report also suggests the kinds of study still needed. The report does
not comment on the appropriateness of the existing standard. Standards for
whole-body exposure are based on considerations of all possible biological
effects and also on policy issues such as degree of acceptable nsk, margin
of safety, and cost-benefit considerations.
13 pp. no figures no tables 55 references
Availability: Committee on Vision, 2101 Constitution Ave., N.W., Ubsh-
ington, D.C. 20418.
86
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Emergent Techniques for Assessment
of Visual Performance
1985
Recent vision research has led to the emergence of new techniques
that offer exciting potential for a more complete assessment of vision in
clinical, industrial, and military settings. Four areas of vision testing are
examined in this report: (1) contrast sensitivity function; (2) dark focus
of accommodation; (3) dynamic visual acuity and dynamic depth tracking;
and (4) ambient and focal vision.
Each of these topics is discussed in a separate section of the report;
each section focuses on issues related to screening industrial and military
visual functions. The report concludes with summary recommendations for
research. The report text is followed by four appendices that give additional
information and detail on spatial contrast sensitivity, detection sensitivity
and response bias, Founer analysis, and the use of tests for screening and
selection.
66 pp. 23 figures no tables 181 references
Availability: Pubh~tion on Demand, National Academy Press, 2101 Con-
stitution Ave., N.W., Washington, D.C. 20418.
87
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Vision Research Reports
E. Porter Horne and Milton ~ Whitcomb, Editors
1960
The purpose of this volume is to bring together the summaries of the
scientific papers that were presented at the 36th, 37th, and 39th annual
meetings of the Committee on Vision. The papers presented at the 38th
annual meeting, which was devoted primarily to the symposium on visual
search, were included in the proceedings of that symposium (see Visual
Search Techniques).
At the 37th annual meeting, in addition to papers summarized herein,
a symposium on illumination and visibility of radar and sonar displays was
held. That portion of the meeting is also reported in Illumination and
Visibility of Radar and Sonar Displays (see below).
This report includes such topics as: recognition of forms against a
complex background; accommodation levels in emptier visual fields; the
status of research on the effect of pre-exposure on dark adaptation; the
intensity factors in vision; and, general color-vision theory.
182 pp. 97 figures 4 tables 260 references
Availability: National Technical Information Service ~IS), 5285 Port
Royal Road, Springfield, VA 22161.
88
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Recent Developments in Vision Research
Milton ~ Whitcomb, Editor
1966
The papers presented in this report concern recent developments
in vision research. Topics covered include: (1) recent advances in the
study of physiological reflex mechanisms in vision, (2) recent advances in
instrumentation and procedures in vision research, and (3) the effects of
drugs on vision.
The papers presented are the following: "Focusing Responses of the
Human Eye," G. Westheimer; "Pupilla~y Movements Associated with Light
and Near Vision: An Experimental Review of the Literature," I.E. Loewen-
feld; "The Fusion Reflex," KN. Ogle; "Vestibular Mechanisms and Vision,"
E.F. Miller II and ~ Graybiel; "Visual Psychophysics with Animals," D.S.
Though; "Measurements of Light Reflected from the Retina," J. Krauskopf;
"Stabilized Image Techniques," T.N. Cornsweet; "Principles of Neurological
Feedback Control Systems for Eye Muscles," L. Stark; "Ocular Pharmaco-
dynamics," NM. Potts; "The Sensory Effects of Drugs: Electrophysiologi-
cal Investigations of the Mechanism of the Action of Drugs on the Eye,"
G.B. Arden; "Studies in the Pharmacology of Extraocular Muscles," G.M.
Breinin and J.H. Perryman; "Drug and Eye Movement Responses in Man,"
G. Westheimer; "The Effects of Drugs on Vision," IFS. Otis; and "Some
Potential of Research on Drugs and Vision," R. Trumbull.
227 pp. 88 figures 10 tables 509 references
Availabd~: AD 627186, National Technical Information Service (NTIS),
5285 Port Royal Road, Springfield, VA 22161.
89
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Vision Research in Military and Government
Laboratories
John Lott Brown
1967
Fairly extensive research on a variety of aspects of vision is conducted
within service laboratories in the Air Force, the Army, and the Navy. There
is also some research on visual processes conducted in laboratories by the
Coast Guard and by the National Aeronautics and Space Administration.
The Committee on Vision requested information concerning their in-house
research; this report summarizes the results of that survey and describes
the type and amount of vision research being done in the military and
government laboratories. References cited in this report indude those
received as a result of that survey. They are neither complete nor a
representative sample of all the work in military laboratories.
22 pp. no figures no tables 63 references
Availability: Committee on Vision, 2101 Constitution Ave., N.W., Wash-
ington, D.C. 20418.
90
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Frontiers of Visual Science:
Proceedings of the 1985 Symposium
1987
Vision research is a science in transition. The improved understanding
of genetics at the molecular level and rapid advances in computer architec-
ture suggest that vision scientists are no longer limited in the methods and
models available to them to tackle the most challenging research questions.
The rate of advance in our understanding of the visual system is not yet
equal, however, to that of technical advance. The transition will be com-
plete when vision research has fully integrated the most promising of these
new approaches and renewed the expansion of its knowledge base.
On December 11, 1985, the Committee on Vision brought together 14
leading investigators in vision research whose work embodies the integration
of some of these newer models and methods. Participants illustrated how
new approaches to fundamental visual processes have significantly improved
our understanding of.spatial vision, stereoscopic depth perception, color
consistency, and color vision. The advantages of these new models are
discussed with methods for attacking problems of vision along many fronts.
The pitfalls and areas in which some of these new approaches fail to explain
visual function are also considered.
The symposium report is divided into three parts, reflecting the three-
part structure of the program: (1) developments in the ideal observer
concept; (2) computational theories for vision research; and (3) cone
pigments and color vision polymorphism.
198 pp. 40 figures 1 table 192 references
Availability: National Technical Information Service (NTIS), 5285 Port
Royal Road, Springfield, VA 22161.
91
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Advances in the Modularity of Vision: Selections
From a Symposium on Frontiers of Visual Science
1990
Converging lines of evidence indicate that the brain contains multiple
neural representations (i.e., maps) of visual space, with different maps
devoted to the analysis of different aspects of the visual scene. From
a computational standpoint, such a processing arrangement makes good
sense given the properties of the brain. Moreover, neurophysiologists
have actually documented that the primate cortex is divisible into distinct
visual maps, with as much as 60 percent of the cortex concerned with
vision. Others are now using noninvasive techniques (e.g., positron emission
tomography) to study local regions of brain activity in alert humans. And
neurologists have known for some time that focal lesions can produce highly
specific losses of visual function.
This is the report of a 1987 symposium that brought together in-
dividuals from these fields—computational theory, neurophysiology, and
neurology—to discuss: (1) evidence for the modularity of vision; (2) topo-
graphic versus nontopographic mapping; (3) the plasticity of modules (i.e.,
to what extend can one module take over the function of another?; (4)
means by which perceptual unification of the visual world occurs; and (5)
the relation of the modularity concept to other functional concepts, such
as focaVambient distinction.
Approve: 70 pp. 31 figures no tables 52 references
Availability: Committee on Vision, 2101 Constitution Ave., N.W., Wash-
ington, D.C. 20418.
92
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Advances in Photoreception: Proceedings of a
Symposium on Frontiers of Visual Science
1990
Vision begins with the transduction of light into neural signals by
photoreceptors. Significant recent advances in our understanding of this
process of photoreception include the precise measurement of the wave-
lengths absorbed by visual pigments in the human eye and the role of the
molecule cyclic GMP in the transduction of light to photocurrent.
Another area of recent progress is the analysis of the spatial mosaic of
photoreceptors. The sampling of the visual image by the photoreceptor lat-
tice influences visual acuity and sensitivity. Disorders of the array of cones
as a consequence of retinal disease may well be the cause of perceptual
deficits. Future research on vision will depend upon these new fundamental
findings about photoreception.
This volume presents the work of scientific leaders on this frontier of
vision research. The 1988 symposium speakers included visual physiolo-
gists and psychophysicists. The volume covers: (1) wavelength specificity
of visual pigments; (2) receptor transduction in health and disease; (3)
adaptation of photoreceptors to light; (4) variations of the photoreceptor
lattice across the retina; and (5) photoreceptor sampling of visual images
and aliasing. Compansons between human and animal retinas are offered,
and differences between photoreceptor function in normal and diseased
eyes are emphasized.
156 pp. 39 figures 2 tables
214 references
Availability: National Academy Press, 2101 Constitution Ave., N.W., Wash-
ington, D.C. 20418.
93
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Representative terms from entire chapter:
microwave radiation
