Introduction to Laser Safety Eyewear

When assessing eye protection requirements for each different Laser type, Laser 2000 uses the latest software to define the necessary L rating (protection level) that should be used as protection against a specific laser or laser operating condition. If you have a laser and are unsure of the level of protection that you require from your eyewear, Laser 2000 will assess the hazard using this software, free of charge.

Defining the correct level of protection is a lengthy and complicated procedure, laid out in detail in a harmonised European standard, CEI/IEC 825 2001. This standard defines the methodology of assessing the hazard that laser radiation presents to the end-user. The standard also defines the methodology of testing laser safety eyewear to define the absolute protection factor or "L" rating that the eyewear provides for specific lasers. This takes both the eyewear filters and the eyewear frames into account to provide a specific L rating for each different combination of wavelength, power and temporal mode of the laser. This differs from the optical density value of the eyewear protection in that it is an absolute measure of the maximum power of the beam that the eyewear can withstand without degradation to the performance of the eyewear.

There are three parts to each L rating.
The first part is the temporal mode of the laser beam:

Temporal Mode Classification Table

The second part defines the wavelength at which the L rating is valid. This can be defined as a single wavelength or as a range of wavelengths.

The final part of the CE rating is the L rating itself which is defined as an L with an integer suffix. This integer value represents the maximum power that the eyewear filters protect against (see table).

For example: D 532 L3: This eyewear delivers L3 protection for a D type beam (continuous wave) at 532nm.

DIR 1000-1300 L5: This eyewear delivers L5 protection for D,I and R type beams across the wavelength range 1000-1300nm.

Defining the L rating depends on a variety of factors. For example, direct exposure hazards are generally worse than reflection hazards and require different levels of protection. Furthermore, emissions from some sources may be "safe" when viewed only in that particular optical arrangement. The introduction of additional optics, could actually increase the hazard to an unsafe condition. The use of optical fibre delivery systems also increases the potential exposure risk to more people whilst further complicating the assessment of the base risk itself.

Understanding the CE mark is the key to understanding the safety provided by each eyewear type. Laser 2000 only supplies laser safety eyewear that conforms fully with the requirements of CEI 825. All laser safety calculations provided by Laser 2000 are conducted to the guidelines set out in the European standard. In preparing this information it must be stressed that Laser 2000 cannot accept any liability or responsibility for any laser safety issues or calculations as the data supplied by the customer may be inaccurate and the method of usage of either the source or eyewear may differ from that described. Your official laser safety officer should check all calculations and the buyer must satisfy themselves that the correct product specification and prices are met prior to purchasing.

Laser 2000 Occular Hazard Calculation Report

• Specifications

• Standard Protection Factor Laser Safety Eyewear (700 & 900 Series Frames / 32 & 39 Series Frames)
• Standard Protection Factor Laser Safety Eyewear (BL-426 / BL-G / BL-E)
• High Protection Factor Laser Safety Eyewear (YL110 / YL300 / YL120H / YL220H)
• Broadband High Protection Factor Laser Safety Eyewear (KBAL)