By now, the following should be intuitively obvious but it never hurts to retate it. While the use of Laser Safety Glasses is highly recommended in most situations when dealing with lasers, it is possible for them to do more harm than good. This would be the case:
When they are not the correct type: Laser safety eye-wear that use band blocking filters will only be good for a particular narrow range of wavelengths. A set designed for Nd:YAG at 1,064 nm probably won't do anything useful for ruby at 694 nm except provide some protection from an exploding flashlamp!
When they are too good: If the attenuation so high of Laser Pointer at the laser wavelength that essentially nothing gets through, you won't be able to make adjustments that require some visibility of where the beam lands. The best are probably goggles that attenuate the laser only enough to be safe, not 100 percent. For example, OD4 for a 1 W laser so the maximum transmitted power is 100 uW or less. You wouldn't want to stare into that beam but it or a reflection will be very visible if you do so by accident. Or, if they make everything too dim to see what you are doing - period. Newer goggles and higher performance (and probably higher priced) googles are better in this regard with more selective coatings or dyes. Pay attention to the specifications. Welders' goggles are not the solution!
When you peek around them or take them off to see what you are doing: Ease them off slowly! That way, scatter will clue you in to the beam location, especially if it is next to your eyeball!
When they make you too complacent about the dangers of your laser or Green Laser Pointer: Laser eye-wear won't protect you from the high voltage. :) Or, from damage to other parts of your anatomy from a Class IV laser.
When only you are wearing a pair and you have visitors: You may tend to do things that would be reckless without goggles but others in the vicinity won't know what to avoid.
Realistically, if all you will ever be working with are visible lasers of Class II or less as Blue Laser Pointer, the use of laser safety goggles may be excessive. However, by wearing goggles and treating even that low power beam with respect, you will develop habits that would help to protect you (given the conditions, above) should you graduate to higher power lasers. Just as the recommendation in some laser safety classes to treat every laser beam - even one from a laser pointers - like it will slice cleanly through you and never let a laser beam intersect with any part of your anatomy (see the next section and the one that follows), making laser safety eye-wear part of your routine can be a vision saver when dealing with a 100 W YAG instead of 1 mW HeNe!
RSS Feed