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IIRC the reason why blu-ray is so disorienting is becuase it makes something in your eyes fluoresce. not completly sure about that though
Blu-ray or Violet (and actually blue too) light is disorienting because it affects the eye differently than longer wavelengths.
It is believed (and I have read that) when light is absorbed by a photoreceptor cell, the cell's pigment will "bleach" and that cell will become non-responsive to light until it is "recharged."
When short wavelength photons are absorbed, photochemical damage may occur...
What happens is that the cell is "recharged" before it is ready and the pigment will accumulate in excess which can lead do the cells dying.
You can test this... It would be interesting to hear others' results...
Take a medium power green or red (50-150mW) and draw a diagonal line in one direction back and forth for 3 or 4 seconds on a blank white wall in low light (stand at a safe distance for viewing).
Blink several times and observe the afterimage.
Do the same thing with a medium-high power violet but drawing the line in the opposite direction so that the after images do not overlap.
When I do this, the after image of the green diagonal line persists much longer and is much stronger than that of the violet.
An afterimage is caused by the photoreceptors "tiring" out and becoming non-responsive.
In the case of violet light, the photoreceptors are re-activated early, so the after image does not persist as long and is not as strong.
Now, I am not well educated in the biology of this phenomenon, so some of this information may contain errors. This is just based on my understanding of what I have read and my own observations...
I can't say how disorienting direct exposure to a 405nm laser is because I have never taken a "direct hit" in my eyes with any violet laser, but I am assuming it sucks based on others' experiences.
I use goggles.
EDIT: TJ- what lens is the laser you're referring to using?
The hi-power lens will give an elliptical beam profile. Acrylic or Aixiz glass will give a rounder profile.
In my experience, the bare diode output (no lens) is always elliptical and never a perfect Gaussian circle.
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