Discussion on Lasers
Your recent discussion regarding lasers has prompted me to post on this list. I’ve had 20+ years experience with lasers from simple diode based pointers to high-powered that will easily cut 3/4" steel plate. I wrote a short piece for a couple of other lists that I’ll copy here that primarily deals with safety issues.
Many people regard a laser as just a bright red flashlight. Sadly, this is far from the truth.
A laser emits an extremely concentrated beam of radiated energy in the form of light. The radiation in some hand held lasers is equivalent to that of direct sunlight. While that initially doesn’t sound disturbing, consider looking straight at the sun for just one second and also remembering what the sun can do to your skin in a few hours.
A hand held laser pointer is designed to project a collated beam a significant distance. The reason that none of them have permanent on/off switches is they are intended to be momentary devices. Quilters have adopted them as a stylus type tool, seemingly without concern for any danger.
It is true that most laser pointers will not cause immediate permanent eye damage, even when viewed directly, however the long term exposure of reflected radiation has not been sufficiently studied yet.
Lasers are classified by the amount of radiation emitted. Most pointers in the USA are class IIIa. Some of those that are very inexpensive ($5 - 10) have such poor quality control that they really fall into the class IIIb designation, which is more powerful.
Most American schools, universities, and government facilities have banned all class III lasers along with all of Australia, Great Britain, and some other European countries, due to excessive radiation. A conservative measure that should make you realize someone has serious safety concerns.
Quilters who are staring at the reflected beam for hours at a time are clear off the charts for expected usage of a laser. A beam that is so powerful that it can be projected for miles is being used to go only inches, so it never really disperses its energy.
There are several ways to protect yourself:
- If you have not yet purchased one, look for a lower power class II laser. They are easy to spot as class II has a yellow "Warning" label while class III has a red "Danger" label. If you are buying online, be sure to ask first.
- If you already have one, place a restriction over the aperture, such as a piece of black tape with a pinhole in it. This is prudent for both class II and III
- To be really safe, buy the special laser protection glasses. I personally would not wear them, but they are available
- Use patterns that are printed on dull paper to reduce reflection
- Rest your eyes often. Be careful to take a minute to let your eyes readjust to natural light before attempting any activity that could be harmful or dangerous without good vision
Please don’t let this discourage you from using a laser, but if you’ve read this far you’ll have a better understanding to provide you with safeguards and prudent use.