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A variety of optical and electro-optical instruments are used for both diagnostic and therapeutic applications to the human eye. These generally expose ocular structures to either coherent or incoherent optical radiation (ultraviolet, visible, or infrared radiation) under unique conditions. We convert both laser and incoherent exposure guidelines derived for normal exposure conditions to the application of ophthalmic sources.

The potential hazards to the eye and skin associated with the use of UV-emitting automotive headlamps are considered. Wide-scale use of high-beam, near-UV headlamps to permit viewing of fluorescence in clothes and fluorescent road markers at great distances can increase automotive safety; however, the potential hazards from exposure of persons to UV radiation must be evaluated. From the study we conclude that such headlamps can be safely designed to preclude human exposure to potentially hazardous levels of UV radiation.

The optical radiation emitted from eight indirect ophthalmoscopes was measured. The levels were compared with the threshold limit values (TLVs) published by the American Conference of Governmental Industrial Hygienists. Many tested instruments were found to emit unnecessarily high levels ofultraviolet and infrared radiation in addition to visible light. The levels of optical radiation emitted from most of the ophthalmoscopes were below the applicable TLVs. Nevertheless, suitable blocking filters can reduce the emission of ultraviolet and infrared radiation. Use of the ophthalmoscopes at the lowest possible power setting and the shortest possible exposure time would further minimize patient exposure.

The spectral irradiance was measured from twenty handheld ophthalmoscopes. The optical radiation emitted from each ophthalmoscope was compared to the threshold limit values (TLV(s)) for acute effects published by the American Conference of Governmental Industrial Hygienists. All ophthalmoscopes tested were found to emit unnecessary ultraviolet and infrared radiation in addition to visible light. The levels of optical radiation emitted from most of the ophthalmoscopes were below the applicable TLV(s). Nevertheless, suitable blocking filters can reduce the emission of ultraviolet and infrared radiation. Use of the ophthalmoscopes at the lowest possible power would further minimize patient exposure.

The purposes and functions of semitransparent eye protective curtains are analyzed. Based upon this analysis, functional requirements are developed, and design requirements are specified for optimum curtains to be used with open arc welding and arc cutting processes. Such curtains also protect against other high intensity broad-spectral-band sources such as compact arc lamps. The requirements for filtering our hazardous UV radiation and blue light must be balanced against the need for transparency in the visible spectrum and the need for reduced glare. Infrared attenuation is shown to be of very little importance.

Methodology for the evaluation of potential optical radiation hazards .has been developed in response to the increasing use of high radiance optical sources, such as lasers, compact arc lamps, tungsten-halogen lamps, and electronic flash lamps. Recent biological investigations of injury from ultraviolet radiation and studies of chorioretinal injury from high radiance sources permit a realistic ocular hazard evaluation. Safe exposure criteria that may be readily applied to practical situations have been developed from the available biological data and from experience with occupational hazards. Hazard evaluation techniques, hazard data, and general control measures are provided for a number of commonly encountered ultraviolet, visible, and infrared sources.