Thresholds of Laser Eye Hazards

Abstract

The eyes of rhesus monkeys and humans were exposed to long-pulsed ruby and neodymium, Q-switched ruby and neodymium, and helium-neon (He-Ne) lasers to determine retinal damage thresholds. Rabbit eyes were exposed to a carbon dioxide (CO2) laser to determine corneal damage thresholds. The data were gathered simulating accidental field exposures. The experimental data show that the white human fundus is appreciably less sensitive to damage from laser radiation compared to the rhesus monkey fundus. In general, the human threshold data obtained are considerably higher than some of the recommended safe levels. Corneal damage levels caused by CO2 laser radiation were reported. The data were shown to be consistent with a simple thermal model. We emphasize that we are presenting experimental observations and are not recommending energy levels for “safe” laser exposures.