405 nm LASER SAFETY

Ah here we go - a solution for everyone's concerns - just make sure you blast yourself with equal amounts red or yellow and you should be fine.

"In 14 experimental Cavia Coba'ya eyes were irradiated with UV-B light, lambda 312 nm, 25 J/cm2 in 15 minute exposure. Including the transmission of light through optical media: cornea, lens, humor aqueous and vitreous body, and pupil surface of 7 mm2, we can calculate that in these conditions retina can be really irradiated with 10 J/cm2. The half number of Cavia Coba'ya was simultaneously irradiated with visible light, lambda of 550-600 nm (1000 Lx). Control group was 5 Cavia Coba'ya. Two months after irradiation, eyes were enucleated and fixed in 4% formaldehyde. Histopathological findings showed alterations of all retinal layers: loss of ganglion cells, axons, reduction of photoreceptors, vacuolar degeneration and hyperplasia of retinal pigment epithelium. In the second group of irradiance, the eyes with visible light lambda 550-600 nm, all retinal alterations were in 50% decreased."

PMID: 17469745 [PubMed - indexed for MEDLINE]

until I got downsized I was Institute of Polymer Science, University of Akron, about 40 minutes south of CWRU.

Steve

I had early cataracts start in both eyes before age 40 -- one ripened enough to get a plastic replacement, the last year before they started adding ultraviolet protection to the plastic (the other eye never got bad enough for the surgery). I see more blue with the operated eye compared to the natural (aging, yellow) lens -- and can see into the ultraviolet with the eye with the plastic lens -- can see the mercury spectral lines, can walk around at night with a UV flashlight using that eye (the normal eye barely sees a faint purple glow, the operated eye sees it as moonlight level purple). (And no, I don't do that; I wear UV blocking safety glasses in ordinary daylight, for that matter. Out of curiosity I got a claimed less-than-5mw violet pointer recently. I've used it for just one single blip pointed at a wall 50 feet away. The normal (aging yellow lens) eye saw a faint violet dot The eye with the UV-transmitting plastic lens saw a bright white dot surrounded by a violet flare. It's scary how much output these things have just past the edge of what's perceptible through normal aging eyes. A child's lens hasn't started to yellow with age -- really cautionary.

I found the "Moscow Incident" described: http://www.laserist.org/2008-07_Russian-incident.htm

The prediction above is fulfilled:
_________
quote:
This guy built a 40 watt laser rifle.
“My Homemade 40W LASER SHOTGUN!!!!!”
https://www.youtube.com/watch?v=iVrJ...ature=youtu.be