Protective eyewear is necessary for Class 3 and 4 laser use where irradiation of the eye is possible. Such eye protection should be used only at the wavelength and energy/power for which it is intended. Eye protection may include goggles, spectacles or prescription eyewear using special filter materials or reflective coatings (or a combination of both) to reduce exposure below the maximum permissible exposure (MPE).
The following factors should be considered in selecting the appropriate laser protective eyewear:
- Wavelength(s) of the laser output
- Potential for multi-wavelength operation
- Radiant exposure or irradiance levels for which protection (worst case) is required
- Optical Density (OD) requirement of the eyewear filter at laser output wavelength
- Need for side shield protection and peripheral vision
- Need for prescription glasses
- Comfort and fit
- Degradation of absorbing media, such as photobleaching
- Requirement for anti-fogging design or coatings
