Black Light safety?

I have a bud who has made his whole apartment
a black light place - he has 24-inch flourescent
black light tubes everywhere - at night that's his
only lighting. I wonder - is there a long-term risk
from viewing black light (the kind sold to consumers) to the eyes?

 

(Tom Malcolm) wrote in

You are talking about a standard fluorescent bulb with a special coating to
filter out everything but the UV. Therefore, there is no more UV coming
from that kind of black light than would be emanating from a standard bulb,
and most of what is generated is long wavelength, low energy UV.

DrG

 

I don't think this is entirely correct. More UV obviously
gets out, else they wouldn't work at detecting UV
fluorescent inks under normal light levels.

Standard mercury vapor fluorescents natively produce _alot_
of UV from the long arc. This is absorbed and re-radiated
by the phosphors coating the inside of the tube. (More
expensive phosphors give a warmer/redder light).

These phosphors are missing in UV fluorescents and are
instead replaced by materials which absorb visible light.
Some of the shortest UV is probably blocked by the glass
tube, but the exact spectrum will depend on what the
manufacturer has used. Consult GE.

I think there is an elevated hazard, especially since
the iris will be dilated and the visual purple clear.
But probably minimal unless the bulb or reflective
surfaces (metal) are within the visual field to inject UV
into the eye. Most surfaces will absorb UV, reducing the
amount the gets into the eye.

-- Robert

 

Typically, the fluorescent tube type UV lights emit at 360nm

Trev

 

Let's make one thing clear: long wave UV is not harmful to the eye. UV-A
and UV-B are potentially harmful. The reason that fluorescent inks are not
detected under normal light levels is because the fluorescence is masked by
the overwhelming amount of light in the visible range.

You are correct here.

I thint that this is much ado about nothing.

DrG

 

Thanks to all for posting on this - the bulbs are 24 inch bought
at a "head shop" - circa 1960's. So I guess I should not be
worried about my friend - as the lights emit what he would
get from a normal flourescent bulb - just not the other frequencies,
just the long wave friendly-to-the-eye light - I'll just tell him
not to stare at the bulbs.

 

Thanks to all for posting on this - the bulbs are 24 inch bought
at a "head shop" - circa 1960's. So I guess I should not be
worried about my friend - as the lights emit what he would
get from a normal flourescent bulb - just not the other frequencies,
just the long wave friendly-to-the-eye light - I'll just tell him
not to stare at the bulbs.
[/QUOTE]

Also tell him not to leave his windows open at night if unscreened when
they are on - UV light attracts nocturnal insect life of all sorts like
you wouldn't believe!

I have heard that prolonged exposure to UV can contribute to corneal
opacity - any opto's care to comment?

--
Regards,
Nicolaas.


- I've got a tiger in my tank. Please don't put the nozzle up his nose!

 

Interesting!

 

Cataracts used to be an occupational hazard for glassblowers as a result of
high exposure to intense infrared radiation. Short-wave, intense UV does
not penetrate very far, and is mainly absorbed by the cornea. However,
some of it does get through to the lens and retina, and is thought to be
contributory to age-related cataracts and macular degeneration.

DrG

 

I have heard that prolonged exposure to UV can contribute to corneal

I know that UV from mercury arc lamps and the Sun can harm the eyes
and everything else - but what about the comsumer-grade UV
flourescent tubes (and even 75 watt painted bulbs)? Do those
put out the same harmful frequencies - or are the consumer sources
more likely to put out wavelengths close enough to visible light
to not harm one's eyes long term. Guess we need to do a study of
those who worked in "head shops" in the 70s to see where their
eyes are now!

 

On 29 Dec 2003, Tom Malcolm wrote

I'd bet that, unless they have been surgically removed they are in the same
place they were in the 70's.

Do you not mean "to see what condition their eyes are in now"?

 

to not harm one's eyes long term. Guess we need to do a study of

When you do the study, please do not efface out the variable that
counts for the use of eyeglasses to correct imperfect sight.

You will see that people using eyeglasses to correct their imperfect
sight will be more prone do the developing of cataracts and macular
degeneration, being these two disease absolutely absent in people
gifted with perfect sight without glasses, contacts or operations.

 

I have a pertinent question.

What would happen if a stare into a 40-watt black light laser for about 4 minutes?

 

If it's 1/10 off a milliwatt - nothing, if it's 1 watt,
good-bye. eyeball. Also, never look down waveguide,
touch electrical stuff with 1 hand in your pocket, etc.

 

And remember not to look into laser with remaining eye.

--
Regards,
Nicolaas.


- You know it's going to be a bad day when the bird singing outside your
window is a buzzard.

 

Still waiting for an answer - I'd like to know if the light
produced by consumer-grade 24 inch flourescent black
lights is harmfull to the eyes long term. Searched the
web and found nothing real on this topic. thanks!

 

Electric?

One hand in pocket?

 

never look down waveguide,

Microwave equipment uses waveguide - usually a long rectangle metal
thing, sometimes the other end is pumping out lots of energy, so one
should never look into a square metal tube hooked up to fancy lab
electronics.

If you try and fix a wall light socket, and the power is on, and you
grab different parts with both hands - the electricity might go
through your heart, stopping it - but if you use just one hand, it will
go through your leg, giving you a much better shot of avoiding
death, etc.