Reflection of laser light from ophthalmic contact lenses

Abstract

Reflections of laser radiation from ophthalmological contact lenses are measured and hazard analysis calculations are presented. Measurements were made on the contact lenses using ophthalmic argon and krypton lasers. Reflection coefficients were around 0.2% for lenses with 'anti-laser' coatings and in the region of 4% for uncoated lenses. It can be shown that the nominal ocular hazard distance for a typical ophthalmic argon laser beam reflected from a contact lens with a flat front surface is approximately 30 cm for a coated lens and 1 m for an uncoated lens. The necessity of protective glasses for attending staff in particular circumstances is reviewed.