When are you eyes in danger?

Curious was mW or light or IR you guys thik is possibly harmful( meaning the use of that laser would need special protective glasses)

>5mw can damage your retina if it directly hits your eye. Anything <5mw is thought of as harmless because your blink reflex will usually save you from any damage.

Here are some general guidelines.
1-You should always use goggles when burning stuff with powerful lasers.
2-Using 5-50mw lasers without goggles can be done if you are extremely careful and watch out for reflective objects. Don't look at the dot on close walls/brightly colored objects either.
3-Always use goggles when using a >100mw laser inside. All it takes is a bad reflection to do instant eye damage at that power level and you can hurt your eyes by looking at the dot on walls.

Razako said:

Don't look at the dot on close walls/brightly colored objects either.

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This depends strongly on the diameter of the dot.

I have a 50mW green and the dot hurts a lot more more than that of a 275mW red. The dot diameter is 1mm vs. 5mm (factor 25)

Zom-B said:

This depends strongly on the diameter of the dot.

I have a 50mW green and the dot hurts a lot more more than that of a 275mW red. The dot diameter is 1mm vs. 5mm (factor 25)

Click to expand...

How much the light "hurts" (as in causes perceivable pain) is NOT an indication of danger to one's sight. The "pain" is NOT caused by the laser damaging the retina. The "pain" is caused by your iris closing tightly and the muscles around the eye tensing up. Your eye simply reacts more (tenses up more) to the green light because it can "see" that wavelength better.

Retinal burns cause very little immediate pain.

Peace,
dave