Eye Protection against Lasers

From published data on threshold dosage for an observable retinal lesion, calculations were made on the attenuation required to protect the human eye against pulsed laser radiation. Several highly attenuating filters were evaluated in terms of the maximum laser energy against which they provide protection. Because of their very high absorption, some of the filters were found to break or craze at relatively low energies. A solution to this problem which provides eye protection against an Nd-doped glass laser delivering up to 740 J in an impact area 5 mm in diameter on the filter is described. Finally, several suggestions are made for protecting the eyes of personnel working with lasers.