TLDR: High power lasers are always unsafe for your eyes. Even the scattered reflection from something seemingly ‘non reflective’ like wood is still powerful enough to hurt and potentially damage your eyes (permanently). Invest in laser safety glasses with the proper wavelength and brightness protection. Send an email to https://store.laserland.com/ with the specs of your laser, they are happy to help you select the right pair of glasses. Another good option is a full enclosure with a $3 webcam inside: https://www.instructables.com/id/Making-Your-Mini-Laser-Engraver-Safer-and-Better/
Getting a new machine is always exciting for me. I had never worked with lasers before and I was determined to not get my eyes damaged by my new toy. After doing some research I concluded that my machine with its own protective screen would be safe enough to work with. This turned out to be the wrong conclusion.
It was quite obvious to me, and I hope also to you, that you should never ever aim a laser to your own or someone else’s eyes. From my online research I learned that the reflection of the laser is also unsafe. This is where I made a mistake. I assumed that watching at the reflection of a laser was in the same danger category as accidentally watching to the arc of an electric welding torch. If you walk in a room where someone is welding and you accidentally look in the welding arc for a fraction of a second from some distance, you should be fine. Even though the light won’t damage your eyes this little exposure is not good and therefore I advise to minimize the exposure to these kinds of lights.
After a couple of short test engravings with my new 3000 MW engraver I selected an engraving that took around 20 minutes. Once the engraver was running I walked away to do something else. All this time I had worked with the machine while standing in front of it but now I was walking in and out of the room and I was unaware that the reflection of the laser beam was visible from the unprotected sides of the machine. When I walked back in the room I, briefly and by accident, looked in the unprotected side of the machine. I noticed that the reflection was really bright and I immediately looked away. At this time I didn’t feel anything strange and my eyes and my vision was OK. After ten minutes I felt that my eyes were itchy and they were hurting a little bit. The feeling reminded me of accidentally poking my eye with my own hand while pulling out a t-shirt. These symptoms disappeared after a couple of days.
For a while, I stop using the machine. This was because I decided that I would only use the machine while wearing laser safety glasses. After my safety glasses arrived I started using the machine again and I advise you to do make sure you have laser safety glasses before you take the machine in use.
The right safety glasses for your laser
Not all laser safety glasses are suited for all lasers. The wavelength, colour and power of your laser are important variables. Most lasers units have a sticker on them with their specs. My laser has a blue colour, a wavelength of 400-460 nm and is 3000 MW strong.
After reading many threads on this laser forum https://laserpointerforums.com I learned that many users are a fan of the brand Eaglepair. I send an email to https://store.laserland.com/ with the specs of my laser and they advised me to buy this pair of glasses:https://store.laserland.com/protection/laser-glasses/laserland/lp-ghp.html
An user from the forum also warned for the cheap brandless safety glasses. Many of them have failed tests and don’t give much/any protection.
The writer of this Instructable https://www.instructables.com/id/Making-Your-Mini-Laser-Engraver-Safer-and-Better/
has built an enclosure with a $3 webcam inside. I found this an excellent option and I’m planning to build this for my machine as well.