EFFECTS OF NUCLEAR WEAPONS ON THE VISION OF SURVIVORS: A REVIEW OF THE LITERATURE
Although serious ocular damage to the survivors of the Hiroshima and Nagasaki explosions was minimal, conditions of these bombings do not necessarily relate to ocular damage to humans and animals reported from subsequent tests. Because of the focusing effect of the eyes' optical system, it is subject to damage at far greater distances from the explosion than any other human organ. Secondary effects were noted in the retina of 400 survivors exposed at Nagasaki and Hiroshima, but these ocular lesions were apparently related to deficiency in blood elements caused by the general somatic effects of radiation and these lesions disappeared without residual damage. Examinations were made of six human cases of chorioretinal burns from accidental viewing of test atomic explosions. One observer, miles from ground zero in Nevada, purposely looked at the fireball with one eye, out of curiosity; a photograph of it is permanently inscribed on his retina. Within 8 weeks his acuity had been reduced from 20/20 to 20/100. Recovery time may vary from a few seconds to several days. The experience of Hiroshima and Nagasaki indicates that many more survivors will suffer extended periods of flash blindness than will suffer retinal burns in any use of nuclear weapons. Visual hazard varies with the size of the explosion, height of the explosion, condition of the atmosphere, dark adaption of the eye, and direction of the gaze. High altitude detonations present possibilities of severe effects since the radiation traverses less of the atmosphere than is the case in an air- burst and consequently less energy is lost by atmospheric attenuation. Rabbits exposed to radiation from a megaton-range weapon, detonated at night at an altitude of 252,000 feet, showed chorioretinal burns at a distance of 345 mi. In this type of hlgh altitude detonation, the energy is released so quickly that protection from the blink reflex or iros constriction, or a shift of gaze is impossible. In the case of large weapons, exploded in the air, the energy is released more slowly in 2 distinct pulses. The first lasts about 1/10 of a sec for a 1-megaton explosion. The first pulse can cause temporary or permanent effects to those viewing the explosion. The second pulse carrying 99% of the thermal radiation, lasts about 10 sec for a 1megaton explosion. The protective mechanisms of the eye, such as the blink reflex and pupil, could operate to reduce exposure during the second pulse, but many persons attracted by the explosion might turn their gaze to look at it and thus cause retinal burns. (BBB)
- Research Organization:
- Originating Research Org. not identified
- Sponsoring Organization:
- USDOE
- NSA Number:
- NSA-17-035466
- OSTI ID:
- 4646368
- Journal Information:
- Am. J. Optometry, Vol. Vol: 39; Other Information: Orig. Receipt Date: 31-DEC-63
- Country of Publication:
- Country unknown/Code not available
- Language:
- English
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