AN IMPORTANT FACTOR IN SPACE PERCEPTION IN THE PERIPHERAL FIELD OF VISION

• Document Type: CREST
• Collection: NGA Records (Formerly NIMA)
• Document Number (FOIA) /ESDN (CREST): CIA-RDP78B05171A000600070031-3
• Release Decision: RIFPUB
• Original Classification: K
• Document Page Count: 20
• Document Creation Date: December 28, 2016
• Document Release Date: April 7, 2003
• Sequence Number: 31
• Content Type: MAGAZINE

Reprinted from THI AMERICAN JOURNAL OF PSYCHOLOGY
Vol. 45, No. 2, April 1933
AN IMPORTANT FACTOR IN SPACE PERCEPTION IN THE
PERIPHERAL FIELD OF VISION
I. E. Fa*E, G. WA and C. HARDY, Johns Hopkins University
pa
ioa w
the o
XUL h they give as to;
pasitbn of the lasts and the symmetry at conformation of the retina.
in a Inter p aim results will be given which bear still more directly on the
importance of the refractive conditions in the peripheral field as a factor in.
peripheral space perception.
With reference to the above needs or any needs of practical application,
the attempts that have been previously made to refract the eye for the pe-
ripheral field are unsatisfactory for the following reasons: (a) the methods
used were either unsatisfactory as to accuracy or so cumbersome as to ap-
A eel for public t'
is true, but clearness of
imagery depends upon the amount rather than the type of defect.
It has been the purpose of the present experiments to study the refrac-
tive condidons in the-peripheral field, One of the reasons for making this
study is the bearing of these conditions on the explanation of the peculiari-
ties and anomalies of peripheral space perception. Other important incen.
tives have been their relation to acuity in the peripheral field; to achromatic
and chromatic Sensitivity in peril vision and to the limits of the form
and color fields; their possible relation to defects of imagery in the central
field and to ocular deviations;, NW the inf
rr
t
t portant rdle because refractive errors in central vision
do not seem to have very much effect on the space perception in the
peripheral field. In this opinion the fact seems to be overlooked that as
compared with central errors of refraction, the errors in the peripheral
field are so great that not much effect could be expected. They modify the
type of error found in the peripheral field it
p la e after. In a recent
Per.' the belief is expressed that the refractive condition in the peripheral
field can not la an m
E
y poorly developed
Vii. With reference to the relative importance of these reasons or
factors, the eoncensus of opinion seems to incline to ti- 1
e
r poor space perception m
P*dOwll field of vision ; defective ima and
er
Tw* 1 Ctant reasons may be given fo th
o f on November 29, 1931. From the Research Laboratory
~'
2 . $IW Optics, Wilmer Ophthalmological Institute, Johns Hopkins Medi.
~? Zioer, B. Cook. D. Millet, and L. Wempie, The perception of form in
l p e*I vision, this JouRNAL, 42, 1930, 246-259.
Declass Review by NIMA/DOD
 SPACE PERCEPTION IN THE PERIPHERAL FIELD OF VISION 229
paratus and procedure as to be worthless for practical work; (b) the re-
sults were not expressed in a form that has practical meaning or value;
and (c) the determinations extended but a short distance into the periph-
eral field. A very important part of our purpose in making the study re-
ported in this paper has been, therefore, the development of a method that
will permit of determinations in the more remote parts of the field, that
will be reasonably satisfactory as to accuracy and feasibility, and that will
give results directly in terms of dioptcr values.
The two most important factors in the ametropia for the peripheral field
are (1) the effect of the oblique incidence of the rays of light from objects
in the peripheral field on the clearness of the image formed; and (2) the
effect of size and shape of the eyeball and of anomalies and irregularities
in the conformation of the retina on the distance of the percipient elements
from the nodal point of the refracting system. With reference to the first
of these factors it will be remembered that clear images are formed by
lenses only when the object to be imaged is located on the principal axis of
the lens. When the object is displaced from the principal axis a distortion
of the image occurs which varies in amount with the angle of displacement
of the object or with the angle of incidence of the light on the lens. In
general, the effect of varying the angle of incidence is that of adding a
weak plus sphere and a strong plus cylinder with its axis at right angles
to the plane of incidence. The major effect is thus to create a strong astig-
matism. A simple formula for this effect in the two meridians may be ex-
pressed as follows:2
F, = F(?_1) 1(?cosb_cosa)
F2 Fl cost a
In these formulas F represents the focal length of the lens in question; F,
the focal length in the meridian of least refractive power; F2, the focal
length in the meridian of greatest refractive power, a, the angle of in-
cidence of the light; b, the angle of rrfraution at the first surface; and ?, the
r::tractive index of the lens.'In both meridians, then, the image is brought
n, a In 'jic greater number of ('yes the effect of this is
bring the earn. ortw?;tti tijc fo,a in the two meridians or to cause a init
astigmatism which inercas