RADIATION THRESHOLDS FOR CHORIORETINAL BURNS.
Rept. for 1 Aug 60-15 Jan 63,
OHIO STATE UNIV RESEARCH FOUNDATION COLUMBUS INST FOR RESEARCH IN VISION
Pagination or Media Count:
Eyes of live rabbits were exposed to electro magnetic rataation of different spectral distri butions to compare their effectiveness in producing chorioretinal burns when retinal image size and in most cases exposure time remained constant. The experiments were limited to the spectral range between 200 and 3000 millimicrons. A carbon Jet-arc served as radiation source in most cases. Results were fffferentiated for three groups of fundus pigmentation. It was found that ultraviolet is virtually ineffective. Th-ffectiveness of the visible and infrared regions of the spectrum is considerably greater, and depends upon wavelength the longer the wavelength the higher the energy threshold measured at the cornea. Present experimental data and related data published by other authors were used to infer a spectral effectiveness func tion for chorioretinal burns. A separate func tion is presented for threshold and for supra threshold burns. The data of this and related experiments are used to derive relations between burn diameter, exposure duration, and burn threshold. A calculational method is described which permits calculation of whether or not a burn is to be expected, based upon physical data on the source such as intensity, size, distance, duration, and spectral composition. Author