http://www.youtube.com/watch?v=Lwze58K8ofo&feature=related


"KEdas" <news.omnitel.net@-trinti-katalogai.net> wrote in message news:hhbbhb$lui$1@trimpas.omnitel.net...
> 
> The refractive index for blue light is enough different from red and 
> green that when they are in focus, the blue is slightly out of focus 
> (chromatic aberration). For an "off the wall" example of this defocusing 
> effect on blue light, try viewing a hologram with a mercury vapor lamp. 
> You will get three images with the dominant green, orange and blue lines 
> of mercury, but the blue image looks less focused than the other two.
> 
> Ir čia: http://texyt.com/bright+blue+leds+annoyance+health+risks
> Are they moaning about nothing?
> 
> What's all the fuss about blue LEDs? Surely a light is just a light, no 
> matter what the color. How can there be a difference between blue and 
> red, green, or amber?
> 
> In fact, blue light causes greater eyestrain and fatigue than other 
> colors. It is harder for the eye to focus and causes greater glare and 
> dazzle effects. It can also interfere with our internal body clocks, 
> disrupting sleep patterns. Some researchers believe that even very low 
> levels of blue light during sleep might weaken the immune system and 
> have serious negative implications for health.