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JBJECTIVE:
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SECRER™ aooopastasee
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SUBJECT :
Fol.
[thermal Effects on the Eye
A. To determine to what degree the flash of a nuclear
detonation impairs the vision and reduces the efficiency of
military personnel during daylight and night operationss
B. To evaluate protective devices developed for the
purpose of protecting the eye against visual impairment resulting from excessive exposure to light.
TEST
PROCEDURE:
Utilizing human volunteers and animals,a number of observa-~
tions have been made,
Human volunteers were exposed during
both daylight and nighttime operations and then studies made
of their visual acuity. In addition, a theoretical and
practical laboratory approach was initiated in 1951 and is
being continued at the U.S.A.F.e School of Aviation Medicine,
STATUS OF
KNOWLEDGE:
Subjective and objective examination of the Japanese
survivors of Hiroshima and Nagasaki demonstrated surprisingly
little evidence of thermal injury to the eyes, In one group
of a thousand persons within two thousand yards of ground
zero no lesions of the fundus were found which could be attri-~
buted to the thermal effects of the bomb, Even the eye lids
(when the patient has sustained severe facial burn) showed
only occasional injury. A history of temporary (a few minutes)
blindness was elicited from a few patients and an occasional
individual stated he was blind for a matter of days.
In this
latter case it was the opinion of the attending medical
personnel that
hysteria might be responsible,
For discussion purposes, thermal eye injury is divided
into three categories |
1. Temporary (flash) blindness: Evaluation of human
volunteers (air crews) at BUSTER established no visual in-
pairment under daylight conditions where other hazards (heat,
blast and radiation) were not encountered.
Under simulated
nighttime conditions at TUMBLER-SNAPPER and UPSHOT-KNOTHOLE,
there was definite temporary flash blindness in unprotected
individuals,
Individuals must be focused so that the detonation is in
the direct forward field of visions Even under nighttime
conditions, there is no impairment of vision unless the fire-
bali is in the forward field of vision,
2.
Retinal Injury:
Four instances of retinal burns in
humans. have been encountered.
Three of these occured wder
complete dark adaptations at Operation SNAPPER and one
occurred under predawn (30 minutes) lighting conditions at
Operation OEtas
In two of the above a permanent