Ocular Effects of Relatively 'Eye Safe' Lasers.

Abstract : Laser devices are an important part of current and future Army systems. Laser rangefinders, designators, communicators, and training devices are currently deployed or are in some stage of development. Most current laser rangefinders and designators, which enhance the effectiveness of the modern Army weapon systems, operate in the visible and near infrared region of the electromagnetic spectrum. The eye is particularly vulnerable in this wavelength region. The collimated laser radiation collected by the eye is transmitted by the ocular media with little attenuation and focused to a small spot on the sensory retina. The retinal irradiance is several orders of magnitude greater than that incident on the cornea; therefore, the total intraocular energy required to produce a retinal lesion is small. Lasers with output characteristic similar to those being fielded are capable of producing serious retinal injury at ranges that are tactically significant (1). The use of binoculars or magnifying optics increases the range at which these injuries can occur. Such devices cannot be used in training exercises without appropriate control restrictions or the use of protective devices. In some cases, training with the actual system in a realistic scenario is inhibited by these restrictions and troop proficiency may never be attained. (Author)