Why do we have to use laser safety goggles?

[MarkmeijerNL]

Hello,it is around 650/660nm

u are Awsome!:yh::bowdown:

 

[Bluefan]

Most of my red's are HeNe's, so I have a bit of a gap at 650-660nm because I don't have many high power red diode lasers.
Most of my spare goggles are either for IR or 532nm and shorter. For higher power 650-660nm I have my ML-7 pair for rgb setups or I use laservision IR goggles still working in the red. Unfortunately I don't have spares for those.
What I have spare for red are these, but those arent usefull for high power 650-660nm diodes or even rated for it, they're for HeNe's or red DPSS.

 

[MarkmeijerNL]

hmm,okay thanks anyways!

do u have other goggles that u dont need?

of wich nano meter are they?

my second opinion of lasers would be an 405 nm
many many many thanks mark

 

[Bluefan]

PM'ed

 

[takato14]

Totally wrong.
A laser emits visible and invisible light radiation and at >100mW, either can be very damaging to your eyes.
Simply looking at the dot of a powerful laser (without safety glasses) can cause permanent eye injury. Reflections off of a mirror or glass can also cause eye injury much faster than you can blink.
See: Laser damage

If you don't want to blind yourself playing with lasers >100mW, you need different safety glasses for each different color laser. Green (or blue) colored lenses protect against red lasers, yellow lenses block bluray (Near-UV 405 +10nm), red colored glasses are good for protection from green or dark blue laser, etc.
Most cheap green lasers have a lot of IR that isn't filtered out. This invisible laser light can fuck your eyes up, and you wouldn't know it until it's too late.


Yes, this is right as diode and filtered DPSS lasers emit a single color of light.

Is this saying that a 100mW laser is safe to use without eye protection? I'm trying to find the highest power laser I can safely use without protection, so that I don't have to worry with laser shades (I wear corrective eyewear so wearing laser shades is either extremely uncomfortable or I can't even see the laser clearly)

If it makes a difference the laser would be green.

Edit: Just noticed how old this topic is. PMing him instead.

 

[Nomad32]

To be completely technical, I believe anything >5mw, glasses/goggles should be worn for indoors, where there's a lot of potential for reflections. At that point it's becoming more than just a pointer, and it can cause damage before the blink reflex kicks in for most people.

 

[Bionic-Badger]

You could have a billion-watt laser and it would be "safe" to operate it without goggles if you could guarantee 100% that none of the light would enter your eyes; however, you can't guarantee that. Goggles are worn to protect you against accidental laser exposure.

What's the highest power you can safely use in general without eye protection? Less than 5mW. Period. That's the rough maximum power that your eyes can be exposed to to which your eyes will react fast enough (blink reflex) to prevent you from suffering permanent eye damage. Note that this limit only applies to lasers that will actually be seen as "bright" to your eyes. For IR or even near-UV (like 405nm) your eyes may not actually perceive something as bright enough to cause a blink until dangerous levels, whereas a wavelength like 532nm may cause a blink reflex for lower powers.

When people talk about 100mW being "safe" they mean it is safe in the context of the laser being aimed at a surface that has been predetermined not to reflect into their eyes. For example, if you're shining your laser into the sky, you probably won't hit anything that'll shine the laser back into your eyes. However, if the beam were to hit something like raindrops, it could easily blind you, like what happened at a rave in Russia.

You can look at the beam of a laser without goggles if you've properly secured your laser. The best way to do it is to wear your goggles, make sure everything is set up correctly, and then sneak a peak. Just make sure you really have it secured! You don't want something like what happened to xoul happening to you because a laser slips from its perch!

Oh yeah, and when you get into REALLY high powers (Class 4, > 500mW) you have to be extra careful. Class 4 lasers are dangerous to the area around them just because of their raw power. This means your eyes can suffer by looking at the reflected light of a Class 4 on a matte (non-shiny) surface. If you want to sneak a peak at a class 4 laser beam, make sure you're not looking at any reflecting surface. With a < Class 4 laser, you can shine it on a wall and looking at the spot generally isn't dangerous (or will trigger your blink reflex). Don't do that with a Class 4 laser. Also make sure your beam terminates on a surface that won't catch fire.