The pathological effects upon the eye of exposure to infrared laser radiation emitted by a carbon dioxide (CO2) laser, was studied. A total of 142 rabbit eyes was irradiated at varying dose levels, and each was observed for a period of two months. Within the limits of the power outputs and exposure times considered, clinically detectable ocular damage was limited to the cornea. Five clinical levels of corneal injury were defined, and the dosage of CO2 laser radiation capable of producing each level of injury was determined.
Leibowitz HM, Peacock GR. Corneal Injury Produced by Carbon Dioxide Laser Radiation. Arch Ophthalmol. 1969;81(5):713-721. doi:10.1001/archopht.1969.00990010715022