Eye protection
Goggles, wavelength matching, optical density (OD).
A direct or reflected hit from any laser used in engraving can cause permanent retinal damage in less time than your blink reflex. The damage is painless at the moment it happens and you only notice later when the dead spot in your vision does not go away.
This is preventable. Wear correct goggles every time the laser is energized.
About this page
Laser engravers and cutters use intense light, often at wavelengths your eye cannot see. Improper use can cause permanent eye injury, severe burns, fire, and property damage.
I am a maker, not a laser-safety or eye-care professional. The guidance below reflects practical experience and published reference material; it is not a substitute for:
- The safety documentation, warnings, and labels that shipped with your machine and your goggles.
- The safety data sheet (SDS) for any material you intend to cut, engrave, or burn.
- Local fire, building, electrical, and ventilation codes.
- Advice from a qualified eye-care professional if you have specific vision needs.
When this page and the manufacturer disagree, the manufacturer wins. Beam Bench (the app and these docs) is provided as-is with no warranty; running a laser is your responsibility. See the terms for the full disclaimer.
Match the goggles to the laser wavelength
Goggles block specific wavelengths. Goggles that block one laser do not necessarily block another. Verify the goggles cover your laser before you wear them.
| Laser type | Typical wavelength | Common goggle marking |
|---|---|---|
| Diode (blue) | 405 nm or 445 nm | OD 5+ at 400-450 nm |
| Diode (red / IR) | 635 nm, 808 nm, 940 nm | OD 5+ at the specific nm |
| CO2 | 10,600 nm | OD 5+ at 10,600 nm, almost any clear polycarbonate blocks this, but verify |
| Fiber (1064 nm) | 1064 nm | OD 5+ at 1064 nm, looks clear to the eye but is invisible IR |
If your machine's laser wavelength is not listed on the machine or in its docs, ask the manufacturer before powering it on. Do not guess.
Optical density (OD)
OD is a logarithmic measure of how much light the goggles block. OD 5 blocks 99.999% (1 part in 100,000). OD 6 blocks 99.9999%. For engraving and cutting lasers, OD 5 minimum at your laser's wavelength.
Cheap "laser safety glasses" sold by the same vendors as cheap diodes are often unrated or under-rated. Buy from a vendor that publishes the wavelength range and OD on the certificate.
What to do
- Wear goggles every time the laser interlock is bypassed or the enclosure is open.
- Wear goggles even with an enclosed machine, interlocks fail, lids get propped, reflected light escapes through gaps.
- Verify the wavelength match before wearing a pair of goggles you have not used before.
- Replace goggles that are scratched, cracked, or yellowed.
- Keep a spare pair for visitors.
What not to do
- Do not wear sunglasses or shop safety glasses and assume they protect against laser light. They do not.
- Do not use the green tinted glasses that come bundled with diode lasers from no-name vendors without verifying OD.
- Do not rely on the enclosure window alone. Most enclosure windows are tinted for visual contrast, not certified OD.
- Do not run the laser briefly "just to test" without goggles. The damage threshold is in milliseconds.
If you think you took a hit
Stop. Note the time and what happened. See an ophthalmologist same-day. Retinal damage from laser exposure is often treatable if caught immediately.