Safety Glasses age

[bcshooter]

After having experienced the Solar eclipse on my birthday in 2017 I noticed the safety glasses had an expiration date and warning not to use past it. I began to wonder after seeing this warning.

Do laser safety glasses have a similar lifespan. Maybe age limit at which they will absorb less than the initial rating when they are new and become more hazardous?

 

[CynicalBrad]

From NASA on the subject.

If your eclipse glasses or viewers are compliant with the ISO 12312-2 safety standard, you may look at the uneclipsed or partially eclipsed Sun through them for as long as you wish. Furthermore, if the filters aren’t scratched, punctured, or torn, you may reuse them indefinitely. Some glasses/viewers are printed with warnings stating that you shouldn’t look through them for more than 3 minutes at a time and that you should discard them if they are more than 3 years old. Such warnings are outdated and do not apply to eclipse viewers compliant with the ISO 12312-2 standard adopted in 2015.

https://eclipse2017.nasa.gov/safety

 

[bcshooter]

thanks

 

[Benm]

Eclipse glasses are a pretty specific thing though. They are often very simple things made from cardboard and some absorbing light absorbing film that may fair over time.

Laser safety glasses and things like welding masks are different: They are supposed to be used continuously in the workplace, not just for 5 minutes a decade or so.

Laser goggles are usually pretty stable things, and unless you intentionally burn a hole through them by pointing lasers at them directly should last a long time.

Active welding glasses may be a bit of a different story though, since they are active devices that basically switch a lcd screen on and off every time they activate - i'm not sure on the lifespan or number of cycles these can last, but it probably is limited.