Comment by tehjoker
25 days ago
There is a small watery layer covering your cornea, this is enough to impede far UV-C (~222nm is safe, 254nm regular UV-C is dangerous to your eye!)
25 days ago
There is a small watery layer covering your cornea, this is enough to impede far UV-C (~222nm is safe, 254nm regular UV-C is dangerous to your eye!)
The tear layer only contributes a little bit--far-UV eye safety is mostly down to the fact that the 222nm only penetrates to outer epithelium (so cells that will be dead in a few days anyway), and the fact that your eyes get very little effective dose if you aren't staring directly into the lamp. You've got eyelids, eyelashes, eyebrows, hair, etc, so the effective dose to your eyes is actually much lower than the dose assumed by most safety standards (ANSI/IES 27.1-22, UL8802), which are fairly conservative. Check out this paper http://onlinelibrary.wiley.com/doi/abs/10.1111/php.13671