Just a quick pic of how different wavelengths affect and damage the eyes.
image_zpsb628ef67.jpg
I'm sure most if not everybody knows but for those that don't please be aware anything above around 780nm - 820nm does NOT stimulate the human blink reflex so both the 1064 Fiber/Yag wavelength and the 10,600 CO2 wavelength will do damage before your brain registers there is a problem. Same with anything under around 380 down into the near UV/UV spectrum.
Like is often said "Do not stare into beam with remaining eye"
cheers
Dave