Project 4.1-- Biomedical Effects - Flash Blindness and Chorioretinal Burns ~ Col. R. S. Fixott OBJECTIVES To gain information regarding the behavior of lid reflexes under the high illuminations produced by atomic devices; to further evaluate the blink reflexes as a protective mechanism against chorioretinal burns. To gain information on shutter and filter mechanisms for eye protection against chorioretinal burns caused by atomic weapons of various types anid yields. f a INSTRUMENTATION The experimental arrangement for this project required the exposure of animal eyes to the weapon detonation at distances which produced retinal lesions in a similar test series during UPSHOT-KNOTHOLE. Rabbits and monkeys were the animals of choice; the former because of ready availability and limited motility of the eye, the latter because of close resemblance to the human eye. Exposure racks were constructed to render nearly complete protection of the animal from whole body effects, when such protection was indicated. limited to one eye of subject rabbits. Direct exposure was The monkeys had both eyes exposed, being used solely for determining the protection offered by the blink reflex. Staggered shutters of two types were used. The simple closure shutters were open at time zero and closed at varying intervals after, up to 1 second. Co The closed-open-closed shutters were closed at time zero, opened at a specified time, remained open for varying durations, LangpehOgrosea. ih