EFFECTS ON THE EYE
John C. Mitchell
The review concluded that acute thermal insult from electromagnetic radiation causes cataracts only when intraocular temperatures reach 45-55°C, with a threshold above 100 mW/cm² for more than one hour, and no cumulative effect below that threshold.
Plain English Summary
Experimental studies showed that lens opacities developed when intraocular temperatures reached 45-55°C, with a threshold around 100-150 mW/cm² applied for 60-100 minutes. The review found no cumulative effect from repeated EMR exposures unless each single exposure caused irreparable injury. Retrospective studies of radar operators and microwave workers found no increased cataract incidence or risk. The authors concluded that heat alone is responsible for lens damage following single high-intensity EMR exposures, based on hypothermic studies showing no cataracts under cooling.
Why This Matters
The data suggest that lower frequencies require more intense radiation exposures to produce comparable lenticular damage because energy transfer to tissue is frequency dependent. Guy's rabbit studies indicated a critical temperature of approximately 43°C for cataractogenesis and an exposure threshold of 150 mW/cm² for 100 minutes. Multiple studies at 100 mW/cm² for durations up to 200 minutes produced no cataracts in rabbits over 12 months of observation. Michaelson reported that no one has been able to produce cataracts by repetitive exposures when the power density is really below threshold.
Finding
The principal conclusions from this effort are: (1) The acute thermal insult from high intensity EMR fields is cataractogenic if intraocular temperatures reach 45-55° C; (2) The EMR exposure threshold is about 100-150 mW/cm² applied for about 60-100 minutes. (3) There does not appear to be a cumulative effect from EMR exposures unless each single exposure is sufficient to produce some degree of irreparable injury to the eye.
In their words
“The principal conclusions from this effort are: (1) The acute thermal insult from high intensity EMR fields is cataractogenic if intraocular temperatures reach 45-55° C; (2) The EMR exposure threshold is about 100-150 mW/cm² applied for about 60-100 minutes. (3) There does not appear to be a cumulative effect from EMR exposures unless each single exposure is sufficient to produce some degree of irreparable injury to the eye.”
Show BibTeX
@article{effects_on_the_eye_g3762,
author = {John C. Mitchell},
title = {EFFECTS ON THE EYE},
year = {n.d.},
}