Ocular injuries from electromagnetic radiation

The effects on the human eye of the various types of electromagnetic radiation are discussed in a fairly general way. The symptoms of increasing doses of X-radiation in the conjunctiva,iris, cornea and retina, as well as the eyelid skin, are described. A delayed effect, appearing after 1-2 years is cataracts, normally resulting from doses of 200-500 rad, dependent on age. Beta and gamma radiation give the same effects as X-radiation, while neutrons and positron radiation lead to more serions injuries. Such injuries appear to be increasing in frequency in Europe. The effects of ultraviolet radiation, mainly in the cornea, are most marked to with wavelengths from 200 to 360 nm, with a maximum at 280 nm. Intense visible light causes injury to the retina, while infrared radiation leads to cataracts. Certain lasers, including cheap diode lasers widely used in measuring techniques, can cause eye injuries. Microwaves, due to thermal effects, can cause injuries to the lens and retina, but the biological effects of radiowave radiation is uncertain. (JIW)