Selecting Appropriate Goggles

• Determine wavelength(s) of laser output. 

• Determine required optical density. To determine the maximum incident beam irradiance, consider the following:

       -  If the emergent beam is not focused down to a smaller spot and is greater than 7 mm in diameter, the emergent beam radiant exposure/irradiance may be considered the maximum intensity that could reach the unprotected human eye.

       -  If the emergent beam is focused after emerging from the laser system or if the emergent beam diameter is less than 7 mm in diameter, assume that all of the beam energy/power could enter the eye. In this case, use the columns labeled "Maximum Laser Output Power / Energy" in attachment 1.

       -  If the observer is in a fixed position and cannot receive the maximum output radiant exposure/irradiance, then a measured value may be used (e.g., downrange from the laser beam).

• Testing Laser Goggles

       Goggles should be checked periodically for integrity. The measurement of goggles filter optical densities in excess of 3 or 4 without destruction of the filter is very difficult. Because of this problem, requirements originally proposed by many laser hazard control guidelines stated that the optical density of goggles be periodically checked have been deleted. The greatest concern has been with goggles having specified optical densities at or only slightly above the density required for protection.

• Identification of Goggles

       All laser goggles must be clearly labeled with the optical density value and wavelength to indicate the level of protection provided. Color-coding or other distinctive identification of goggles is recommended for multi-laser systems.