# Is full spectrum flourescent light safe for human eyes?



## picard (Oct 25, 2006)

Do the eyes get fatigue from long use of full spectrum flourescent desk lamp?? should I use full spectrum light instead of LED light. I am caught in a dilema.


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## will (Oct 25, 2006)

that is a good question - I would assume that full spectrum means the same as daylight, which should not have any adverse effect on eyes. 

Flourescent lights all flicker at 60 HZ. that might cause eye strain. that is why you will often see desk lamps using incan lights,


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## jtr1962 (Oct 25, 2006)

will said:


> Flourescent lights all flicker at 60 HZ. that might cause eye strain.


Not with electronic ballasts. They drive the tubes at roughly 25 to 50 KHz. Above a few KHz the phosphor persistence of the tubes causes them to stay lit continuously.

To answer the original question, if the full-spectrum desk lamp uses an electronic ballast _and_ true full-spectrum tubes then you will be better off than with an LED desk lamp. However, be aware that often unscrupulous tube manufacturers slap the term "full-spectrum" on any tube with a CCT of 5000K to 6000K when they should restrict the label to tubes with a CRI of 90 and above. Compared to full-spectrum fluorescent, LEDs are a bit more deficient in reds, and usually somewhat bluer. However, given the choice between LED or incandescent I'll pick LED every time despite its deficiencies. Things just look fuzzy under the yellowish light coming from an incandescent, not to mention the problems of heat and relatively short life.

All that being said, if you can find a desk lamp with LEDs of around 5000K to 6000K CCT instead of the usual 8000K or 9000K then it wouldn't be that much worse than full-spectrum fluorescent. Maybe the CRI would be around 85 instead of 90 but unless you're doing very critical color matching your eyes wouldn't notice.

Are full-spectrum lights bad for your eyes? Not any more so than regular fluorescents or any other kind of light. Remember that sunlight contains much more UV than fluorescent yet people can work outdoors for years without suffering any ill effects so long as they don't look directly at the sun.


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## will (Oct 25, 2006)

jtr1962 said:


> Not with electronic ballasts. They drive the tubes at roughly 25 to 50 KHz. Above a few KHz the phosphor persistence of the tubes causes them to stay lit continuously.
> 
> To answer the original question, if the full-spectrum desk lamp uses an electronic ballast _and_ true full-spectrum tubes then you will be better off than with an LED desk lamp. However, be aware that often unscrupulous tube manufacturers slap the term "full-spectrum" on any tube with a CCT of 5000K to 6000K when they should restrict the label to tubes with a CRI of 90 and above. Compared to full-spectrum fluorescent, LEDs are a bit more deficient in reds, and usually somewhat bluer. However, given the choice between LED or incandescent I'll pick LED every time despite its deficiencies. Things just look fuzzy under the yellowish light coming from an incandescent, not to mention the problems of heat and relatively short life.
> 
> ...




That is a more complete answer - 

I thought that flourescents tended to give light in a given wavelength. that the tubes were tinted to get the different colors (K) warm white, cool white, daylight, aquarium lights, palnt lights etc...


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## lpcmidst128 (Oct 26, 2006)

Older magnetic ballast tend to flicker which is annoying which gives fluorescents a bad reputation. Right newer electronic ones are more efficient, no humm and no annoying flicker.

Full spectrums sometimes called sunlight, natural, sunshine, etc... usually are at 5000-5500K. The higher the CRI the more true the color. The thing I notice is that the red colors and blue colors are stronger in full spectrum compared to the ordinary cool white.

So I believe that full spectrum is better for your eyes than cool white or warm white. Keep in mind Daylight (6500K) is different from Full Spectrum, Natural Sunshine, etc..(5000-5500K).


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## eluminator (Oct 26, 2006)

will said:


> I thought that fluorescents tended to give light in a given wavelength. that the tubes were tinted to get the different colors (K) warm white, cool white, daylight, aquarium lights, palnt lights etc...



Fluorescents use a combination of several different phosphors (fluorescent materials) to give a reasonably full color spectrum. Depending on the phosphors used, you can get cool white or warm white, etc.

The so-called white LEDs are somewhat similar except I think they only use one phosphor. Of course the LED itself generates blue light and this excites the yellow phosphor painted on top of the LED. White LEDs seem to give a strange light to my eyes. I prefer CFL.


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## will (Oct 26, 2006)

thanks for the additional information.


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## picard (Oct 28, 2006)

thanks for the information guys. Is there a way for me to identify flourescent lamp use electronic ballast? or do I have to ask the manufacturer for info?


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## snakebite (Oct 28, 2006)

one tip is that electronic ballasts are lightweight.
as far as safety i get less eyestrain when doing fine work with the 950 fluorescents than under cool white.hint..950 phosphor tubes are what many so called "full spectrum" makers relabel and mark up 10x$$$$


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## hank (Nov 4, 2006)

Sometimes "full spectrum" means the light emits significant ultraviolet (the mercury vapor emission lines) . That's simply dangerous. Sometimes it means only "high color rendering" -- triple or quadruple phosphors all emitting in the visible light range. 

Two sources that go into the health and vision issues -- the first one is new to me and has the best summary I've seen of the physiology and how the visual receptors do and don't match what various light sources produce.

http://www.psycheducation.org/depression/BlueLight.htm

http://www.mdsupport.org/library/hazard.html#blue


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