Human Eyelids and UVB/UVA Transmittance: There Isn't Any

This is an interesting fact that could be relevant to more basic research on these topics. This area is so complicated that it's challenging to write about, and that's why I haven't discussed it or written about it more up to now. But it's interesting that human eyelids transmit almost zero UVB and UVA (it's less than one percent--0.4 percent of some wavelengths, I think) but do transmit the visible wavelengths [Prystowsky et al., 1992: (http://www.ncbi.nlm.nih.gov/pubmed/1597547)]. There's similar research on eyelids from young lambs or some strange thing. Prystowsky et al. (1992) did eye exams on those patients (or reported on eye exams that had been done, etc.) and performed the experiments using actual human eyelids that had been removed during elective surgeries, etc. I should mention that the authors of that article say that, although normal intensities of visible light would be scattered as they pass through the eyelids, making retinal burns unlikely, one would obviously not be protected from retinal burns if one looked at the sun with one's eyes closed. I doubt anyone would do that, but that type of fact about eyelids might be useful for research on the trigeminal system, etc. I mean, as long as a person didn't look up at the sun, with one's eyes closed, one wouldn't get retinal burns. I guess that if one didn't have wheels, one wouldn't be a wagon, either. ("If my grandmother had wheels, she'd be a wagon.") That's a little joke, and that research article is probably not relevant to anything. I didn't come up with that quote, incidentally, so I hope it doesn't offend people's sensibilities.