Blue LEDs on M Series (Purkinje effect)

jskinner · Post by **jskinner** » Thu Aug 30, 2007 9:18 pm

Maybe the following explains why some find the Blue LEDs on the M Series so annoying...

http://texyt.com/bright+blue+leds+annoy ... alth+risks

Perchancetodream · Post by **Perchancetodream** » Thu Aug 30, 2007 9:42 pm

If yellow tinted shooters glasses help filter out the blue light, wouldn't yellow cellophane do the same?

I may try it tonight because my husband has an alarm clock, yes an alarm clock, with bright blue LEDs. So far I have just covered the face with a piece of dark fabric, but that means that it doesn't work well as a clock.

Susan

Snoredog · Post by **Snoredog** » Thu Aug 30, 2007 9:48 pm

I've been saying that since day one on the Respironics M series machines, LOL tells you how much research they did on it

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.

...Blue light, sleep disorders, and cancer
The chain of cause and effect which might link blue light to serious conditions like cancer is a long one, and far from proven. Blue light's effects on circadian rhythms and sleep, however, are quite firmly established.

Putting blue LEDs on a radio alarm clock isn't a great idea.

Light centered in the blue part of the spectrum is known to suppress levels of melatonin in the body. Melatonin, sometimes referred to as the 'sleep' hormone, plays a key role in regulating the sleep cycle.

In summary, when melatonin levels in your body are high, you sleep; when they are low, you wake up. Blue light appears to be a kind of natural alarm clock, which wakes animals as the sky becomes blue after sunrise. Only a fairly narrow band of frequencies centered around 'pure' blue has this strong impact on melatonin.

LOL Respironics deserves an award for incorporating BRIGHT BLUE LED's into a sleep product, that is almost as ingenious as increases prices so we all can get better service.

Snoredog · Post by **Snoredog** » Thu Aug 30, 2007 10:01 pm

Perchancetodream wrote:If yellow tinted shooters glasses help filter out the blue light, wouldn't yellow cellophane do the same?

I may try it tonight because my husband has an alarm clock, yes an alarm clock, with bright blue LEDs. So far I have just covered the face with a piece of dark fabric, but that means that it doesn't work well as a clock.

Susan

I think the amber shooters glasses are to filter out the blue light spectrum from the eye and that improves your vision.

It is why target and trap shooters wear them, you can see better with the blue spectrum of light filtered out.

But let us know how it works putting it over the blue LED's on your alarm clock, you'll probably wake up not needing glasses

Perchancetodream · Post by **Perchancetodream** » Thu Aug 30, 2007 10:09 pm

Snoredog wrote:
Perchancetodream wrote:If yellow tinted shooters glasses help filter out the blue light, wouldn't yellow cellophane do the same?

I may try it tonight because my husband has an alarm clock, yes an alarm clock, with bright blue LEDs. So far I have just covered the face with a piece of dark fabric, but that means that it doesn't work well as a clock.

Susan
I think the amber shooters glasses are to filter out the blue light spectrum from the eye and that improves your vision.

It is why target and trap shooters wear them, you can see better with the blue spectrum of light filtered out.

But let us know how it works putting it over the blue LED's on your alarm clock, you'll probably wake up not needing glasses

You're right, clearly I need more rest if I want to understand what I read!!

What we will get is a new alarm clock!

Susan

andyomega · Post by **andyomega** » Fri Aug 31, 2007 1:43 am

why does everyone complain about them? I think they are great ! I love how they light up the inside of my night table drawer when its closed with machine inside.

roster · Post by **roster** » Fri Aug 31, 2007 5:31 am

We owned a sailboat for 15 years and loved to sail at night because there were few people on the lake and we could also avoid the hot sun.

All of the instrument lights were red. We were told this was because red light will not cause your iris to partially shut off light to your pupil. Of course we wanted our eyes wide open to be able to see objects on the water.

socknitster · Post by **socknitster** » Fri Aug 31, 2007 9:05 am

I just shot respironics another email about this. And a rant about the software. LOL.

Feeling ranty lately. Gotta catch up on sleep since the surgery. . .

Maybe this long weekend will help!

Jen

jasper · Post by **jasper** » Fri Aug 31, 2007 9:45 am

Already put a piece of electrical tape across the 3 main buttons. I'm ready to put tape on the humidifier dial too. Even that one small LED is too bright! Good article James thanks...

Goofproof · Post by **Goofproof** » Fri Aug 31, 2007 10:16 am

Thanks, James for the read. I like Blue leds, but it's something that may need changing, I don't use the "M"agic offender, but I Have a Braun Shaver charger that can be seen at five miles out, my stereo power indicator also serves as a night light

As a Viet Nam vet, I am still aware of light control, I used to drive a CAT 785D, 150 ton Dump truck at night, we had 8 drivers working big trucks. On nights when we had a full moon we would operate running with just our marker lights on ot preserve our night vision. The bosses didn't think much of us doing it, but they never liked us driving of the wrong side of the roads at night. Bosses, they are hard to train. Jim

The Cat785D has 4 headlights 5 foot off the ground, and 4 more 12 foot off the ground. They were night vision killers.

VenDexter · Post by **VenDexter** » Fri Aug 31, 2007 10:45 am

Yes, our eyes are definitely more sensitive to the green-blue end of the visible spectrum but the fact that blue lights are causing sleeping problems, melatonin deficiencies, and immunosuppression are full on bunk.

The site refers to IDA as being the source of the idea that blue light affects sleep. Nothing on the IDA sight shows a clear connection of blue light and sleep rhythms. IDA does maintain that "light pollution" in all its forms has had a major impact on modern society, especially circadian rhythms. They advocate for wise use of artificial lighting in all its forms.

cascade · Post by **cascade** » Fri Aug 31, 2007 11:19 am

Excellent link, James -- thanks for providing it!

On some poorly designed products they are far brighter than they need to be, and they stay on all the time.

Maybe the Respironics designers thought "looking cool" trumped "purpose."

Snoredog · Post by **Snoredog** » Fri Aug 31, 2007 11:22 am

VenDexter wrote:Yes, our eyes are definitely more sensitive to the green-blue end of the visible spectrum but the fact that blue lights are causing sleeping problems, melatonin deficiencies, and immunosuppression are full on bunk.

The site refers to IDA as being the source of the idea that blue light affects sleep. Nothing on the IDA sight shows a clear connection of blue light and sleep rhythms. IDA does maintain that "light pollution" in all its forms has had a major impact on modern society, especially circadian rhythms. They advocate for wise use of artificial lighting in all its forms.

Not so, studies show blue light can be used to "reset" circadian rhythms, by applying blue light you reset yourself back to daytime/daylight which is the opposite of what you want when trying to sleep.

http://www.hno.harvard.edu/gazette/2003 ... light.html

"The visual system in humans is most sensitive to green light," notes Steven Lockley of Brigham and Women's Hospital, a Harvard research and teaching affiliate. "But when we exposed 12 healthy young men and women to the same amount of either green or blue light, their 24-hour rhythms shifted twice as much with blue than with green."

VenDexter · Post by **VenDexter** » Fri Aug 31, 2007 11:57 am

I should have emphasized the point about the site using claims like "clearly established" "definitely" etc.

I certainly don't disagree that light pollution in any form can affect our circadian rhythm but the site was singling out blue LED's with nothing concrete to back it up. They are basically implying that blue LED's are the current bain to our sleeping existence and are causing us to have immunosupression, etc. I'm still claiming that they are spouting bunk.

As far as the Harvard sample, it was 24 young, healthy people. This is hardly conclusive but certainly promising research.

There has been lots of research done on people with Seasonal Affective Disorder which conclusively shows that light striking the reticular activating system can help them regulate mood but nothing that shows any correlation to immunosuprression (depression/stress is good enough at that in and of itself).

Sleep, or lack thereof, has always correlated with our ability to defend ourselves immunologically but to extend this to say that blue LED's cause us to be immunosuppressed is pulling it out of thin air.[/b]

jasper · Post by **jasper** » Fri Aug 31, 2007 12:01 pm

Regarding the comment about using a yellow filter to cut down on the blue light output: yes, it works. A yellow filter is used in subtractive filtration for color printing to cut down on the blue light.

So, to get back to the original thought posted by perchance... sounds like yellow cellophane is worth a try. Let us know how it works out.

Mask