On the effect of ionizing radiation upon the retina in man and animals.

The phenomenon of light flashes observed by the American cosmonauts on exposure to primary cosmic radiation during translunar flights, and also perceived by other observers on exposure of the eye to neutrons from accelerators, is indeed one of the latest manifestations of the sensitivity of the retina to very high energy radiation. The usual interpretations of this phenomenon are based either on the hypothesis of Vavilov-Cherenkov radiation in the ocular media, or on the direct stimulation of photoreceptors in the retina itself. The data available are submitted to adequate analysis, the experimental materials concerning the radiobiology of the retina are generalized, and a conclusion is drawn as to the most probable mechanism of light flashes considered as signals damaging the outer segments of the rods by particles arising from nuclear reactions in the retina.