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FrozenGate by Avery

'BluRay' lasers and eye damage(!)

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There's increasing evidence that 405nm radiation is much more damaging to the health of your retina than green or red light.

See these two links:

Information for Therapists on Light Therapy and Retinal Damage
Blue Light Therapy and Age-Related Macular Degeneration - AMD

from the second link:
Age-related Macular Degeneration (AMD) is a condition of advanced degeneration of the macular portion of the retina that leads to progressive blindness in over 35% of persons over the age of 75.1 AMD has been linked to the stress engendered by radical oxygen species in macular photoreceptor cells and proximate retinal pigment epithelium cells (RPE).2 Both of these types of cells are non-replicating (post-mitotic) and must respond to a lifetime of oxidative insult, which includes light-induced oxidative stress.3 While there are numerous mechanisms in the retina for preventing and forestalling oxidative insult, by middle-age many of these anti-oxidative mechanisms have begun to break down, which increases the susceptibility of the retina to accumulated damage with increasing age.4

Visible light absorbed by photoreceptors is a significant factor in the production of reactive oxygen species that induce the molecular damage in retinal tissue which appears to contribute to the formation of AMD.5 To an overwhelming degree, blue wavelengths of light produce the most oxidative stress within the retina and are primarily responsible for exacerbating the extent of oxidative damage that has begun to occur.6 Since blue light wavelengths impart the greatest risk of photochemical damage, the risk of retinal damage from light is termed "the blue light hazard", with the greatest hazard peaking at wavelength of 440 nm.7
Click to expand...

Note the peak wavelength for retinal damage is around 440nm! Apparently below about ~470nm light is much more 'toxic' to retinal cells, especially for chronic long term exposure. This is really something to be aware of.

Protect your eyes!

I'd also suggest people take a look at this thread regarding some of the unique dangers of powerful blue lasers:
http://laserpointerforums.com/f65/plea-eye-safety-51464.html

It appears green and red lasers are more eye safe than blue ones.
 





Good info, however 'blu-ray' lasers are in the 405nm range. The 445nm diodes from the Casio projectors are more of a hazard.
 
Oh noez! Don't look at the sky!... or... any source of white light ever again!
 
Cyparagon said:
Oh noez! Don't look at the sky!... or... any source of white light ever again!
Click to expand...

The slice of spectrum they're talking about is a very small part of what light there is from the sky or any other white light source. 1 watt of 445 however is MUCH more concentrated than anything you ever get from natural or incandescent sources.

I saw a post in one of the 445 threads that caught my attention after having read about the dangers of blue light before.

Let me try to find it again.

here it is.

http://laserpointerforums.com/f65/merged-445nm-pictures-video-thread-51335-12.html#post717064

The 'leaves trails in vision' comment is exactly what this article is talking about. Long term exposure to high levels of light in this range will slowly cause permanent damage to your vision.
 
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qumefox said:
The slice of spectrum they're talking about is a very small part of what light there is from the sky or any other white light source. 1 watt of 445 however is MUCH more concentrated than anything you ever get from natural or incandescent sources.

I saw a post in one of the 445 threads that caught my attention after having read about the dangers of blue light before.

Let me try to find it again.

here it is.

http://laserpointerforums.com/f65/merged-445nm-pictures-video-thread-51335-12.html#post717064

The 'leaves trails in vision' comment is exactly what this article is talking about. Long term exposure to high levels of light in this range will slowly cause permanent damage to your vision.
Click to expand...

Damn. That really makes me wonder where to draw the line with these diodes... for instance I'm thinking that simply viewing the beam in thick fog (at night) might be enough to be a problem in the long term.
 
I partially agree with you, however the reflected atmospheric fog or dust/smoke particles in the beam facing away from you are probably much less of a hazard than the projected beam spot or termination point.
In other words, I'm saying that looking at the beam projected into the sky is the best way to observe ~445nm for longer term exposure, and looking at the beam projected towards you, say in the tunnel effect is much more hazardous, and looking at a terminated/beam spot closer than ~15 feet on a surface that has a reasonable specular reflection is the worst in an unsuspecting spectator. Assuming we are exempting the obvious. A direct mirror like reflection or direct full frontal impact of the beam on the retina. One way I look at the danger with the blue spectrum is that, on the color wheel, orange is the opposite of blue and close to the red spectrum of the blood vessels of the retina. In other words, I'm guessing that blue photons are well absorbed by the red hemoglobin vessel of the retina that supply blood to the rods and cones of the eye. One note about this is that we are talking about ~445nm wavelength in a ~405nm forum, and for that I apologize for being slightly off-topic.
laze_doctor said:
Damn. That really makes me wonder where to draw the line with these diodes... for instance I'm thinking that simply viewing the beam in thick fog (at night) might be enough to be a problem in the long term.
Click to expand...
 
So the beam spot is definitely dangerous in these high-powered lasers. What about the beam itself in indoor viewing conditions? I mean, terminating the beam in a real beam dump (no spot) and viewing the actual beam with fog or a smoke cartridge from a few feet away. Would that be safe for a 200mw 405nm beam? What about a 1w 445nm beam?
 
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Here's how I explained it before. If it was really such a hazard then it would be bad just looking at the picture from the projector. The only way you'd really need to worry about it is if you're doing stuff that you shouldn't be doing anyway like looking at the spot up-close without goggles or if you take a reflection to the eye.
Looking at the beam and the light in general=fine.
 
laze_doctor said:
Damn. That really makes me wonder where to draw the line with these diodes... for instance I'm thinking that simply viewing the beam in thick fog (at night) might be enough to be a problem in the long term.
Click to expand...

It's when the light is concentrated that that your going to have problems. Viewing the beam itself, even in fog, isn't really a hazard due to the fact very little of the power is being reflected back. However viewing the dot itself without goggles at anything less than 50 feet probably isn't advisable.

Razako said:
Here's how I explained it before. If it was really such a hazard then it would be bad just looking at the picture from the projector. The only way you'd really need to worry about it is if you're doing stuff that you shouldn't be doing anyway like looking at the spot up-close without goggles or if you take a reflection to the eye.
Looking at the beam and the light in general=fine.
Click to expand...

Diffuse light isn't a problem, at least in the short term, but yes, it's the concentration of light that poses the problem.

If you maintain the level of eye safety you should when dealing with ANY laser class 3B or higher though... the danger should be minimal.
 
*Sigh* one more thing that I can't do that will eventually kill me / blind me / make me sterile / make me sick / disable me / etc.

make these black
bubble_boy.jpg
 
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