Google search for "blue light" +"eye damage"
http://www.bbc.co.uk/dna/h2g2/A762662.
"Nichia Corporation of Japan, one of the pioneers of the blue/green LED, now produce a true green LED that is so bright that it cannot be viewed for more than a few seconds without eye damage occurring."
and on looking for a source for that, this:
http://www.go-led.de/datenblatt/W500BS.pdf
"The LED light output is strong enough to injure human eyes. Precautions must be taken to prevent looking directly at the LEDs for more than a few seconds." -- Specifications For Nichia White LED
-------------------------------------------------
http://www.open2.net/science/backgroundbrief/sun/story.htm
"St Thomas's Hospital in London.... John Marshall demonstrated how human sight works....
"at the back there's the retina, which is concerned with detecting an image and sending it to the brain. ...
"... the damage is caused by the concentrating effect actually causing changes in the retina at the back of your eye.
"... and we think that the retina can be harmed over time by overexposure to light, particularly blue light.
"... if you've damaged your retina, there's no pain perception, and the only way you'll know is because some dysfunction in your vision. An optician will be able to investigate the condition further. But unfortunately if you have damaged the back of your eye, it's permanent."
------------------------------------------------
http://www.femto.sims.nrc.ca/LaserSafety/lsafety7.htm.
"Wavelengths between 400 nm and 550 nm ...
are particularly hazardous for long-term retinal exposures or exposures lasting for minutes or hours. They can cause photochemical injuries to the retina (i.e. blue-light photoretinitis) which may lead to permanent blind spots (scotomas)."
------------------------------------------------
http://www.twi.co.uk/j32k/protected/band_13/faq_radiation.html
"Intense visible light particularly approaching UV or 'blue light' wavelengths, passes through the cornea and lens and can dazzle and, in extreme cases, damage the network of optically sensitive nerves on the retina."
-------------------------------------------------
http://www.nrpb.org/publications/documents_of_nrpb/abstracts/absd13-1.htm
"... gazing at very bright light sources, particularly those emitting shorter wavelength blue light, causes retinal damage resulting in transient or permanent loss of visual acuity. ... Similar damage has also been induced in the non-human primate retina following acute exposure, particularly to blue light."
------------------------------------------------
http://prism.mit.edu/cmse/CHSP0601/7.pdf.
"Researchers must be aware of the "blue light" hazard. The threshold for eye damage is 100 times lower for blue light than for red or near-ultraviolet. For example, the diffuse reflection of a multiwatt argon ion laser beam falling on a black beam stop can be an eye hazard."
------------------------------------------------
www.caves.org.uk/led/led-myths.html
"A white LED is, in reality, a blue LED (light-emitting diode) surrounded by a phosphorescent dye that glows white when it is struck by blue light. .... people have noticed the pronounced blue peak in graphs of the power spectrum...."
-------------------------------------------------
www.rockefeller.edu/lab/NONRAD/nonrad.html
"Visible light (400-780 nm) ... pass through the cornea and lens and are focused on the retina. Due to this focusing, light energy that reaches the back of the eye is increased by a factor of 100,000 over the energy incident on the cornea. Thus, significant retinal damage is possible from low radiation levels. ...
"For visible (white) light, threshold limit values (TLVs) are only recommended1 if the luminance of the source exceeds 1 candela (cd)/cm2. Threshold limit values have been proposed for blue light..."
--------------------------------------------------
http://www.stao.org/safeart6.htm.
"The blue light threshold for retinal damage is several orders of magnitude below that for red light or IR. The primary site of injury is the photoreceptors ....
"Waveband: Blue Light
Acute Effects: Photochemical
Chronic Effects: Retinopathy (damage to photoreceptors); Age-related macular degeneration."
-------------------------------------------------
http://dinc.com/maf/1999/nl_06_03.htm.
"Each eye contains a small patch of specialized tissue in the back of the eyeball at the center of the retina called a macula. Deterioration of the macula in the retina can result in partial or complete blindness. Those over 60 are most vulnerable to this condition, called age-related macular degeneration (AMD) - which has no cure ....
Inspection of eye tissues reveals high concentrations of some carotenoids, which act as antioxidants to reduce damage to eye cells by free radicals resulting from factors like sunlight. It appears that those who eat a diet containing lots of carotenoids have the healthiest eyes....
"It isn't clear why carotenoids are especially eye-healthy, but it is theorized that they may function as filters that protect the eyes from blue light, which is a band of radiation from sunlight that can cause eye damage."
-------------------------------------------------
"Think of it as evolution in action."
- Larry Niven and Jerry Pournelle, _Oath of Fealty_
"THINK!"
- John Watson, IBM
Please don't just blow by this long posting, folks.
Notice that your retina is 100x more sensitive to damage from blue than from red light,
and
Notice that there is no immediate warning, no pain associated with retinal damage, only a slow, incurable loss of the ability to see.
