Welcome to Laser Pointer Forums - discuss green laser pointers, blue laser pointers, and all types of lasers

LPF Donation via Stripe | LPF Donation - Other Methods

Links below open in new window

ArcticMyst Security by Avery

Are these uv flashlights safe for the eyes?

Razako

0
Joined
Mar 17, 2006
Messages
4,301
Points
113
http://www.dealextreme.com/details.dx/sku.10709
I have one of the above uv lights and whenever I use it for a short amount of time my eyes start feeling really tired and the light seems to mess with my ability to focus on stuff. My eyes do return to normal after I stop using the light and I'm wondering if you need some kind of eye protection for these lights. It seems just like any ordinary blacklight or blu-ray so I'm not sure what the problem is. I also notice people in the reviews complaining about it hurting their eyes.
 





Joined
Sep 22, 2007
Messages
977
Points
0
The LEDs are probably in the 260-385nm range with plenty of bleed into the violet. Of course they don't say on the dealextreme website. The light is not coherent nor focused so there's no worry about UV burns to the cornea but I suspect you do get an optical response from the cornea and lens (both of which are opaque to UV). It would probably save many headaches and eyestrain to use a set of UV protective glasses since the fluorescence you are looking for is outside the UV range and would be visible while using UV protection.

You could use a set of UV blocking sunglasses or purchase a set of UV protective glasses, which are clear.
 

Razako

0
Joined
Mar 17, 2006
Messages
4,301
Points
113
FrothyChimp said:
The LEDs are probably in the 260-385nm range with plenty of bleed into the violet. Of course they don't say on the dealextreme website. The light is not coherent nor focused so there's no worry about UV burns to the cornea but I suspect you do get an optical response from the cornea and lens (both of which are opaque to UV). It would probably save many headaches and eyestrain to use a set of UV protective glasses since the fluorescence you are looking for is outside the UV range and would be visible while using UV protection.

You could use a set of UV blocking sunglasses or purchase a set of UV protective glasses, which are clear.
Ok thanks. Just wanted to be sure that this thing won't do any permanent damage to people's eyes. I have a pair of novalasers goggles block the uv light from this and they seem to eliminate the eye strain. Only problem is that they also block out all of the blue and green fluorescence effects.
 

Razako

0
Joined
Mar 17, 2006
Messages
4,301
Points
113
Joined
Sep 22, 2007
Messages
977
Points
0
Well then, I'll guess you'll just have to go out and build yourself a CO2 laser system then to justify the goggles, lol.
 

Benm

0
Joined
Aug 16, 2007
Messages
7,896
Points
113
It depends on the wavelength really, if it is well below 400 nm i'd suggest using eye protection. On the long run, exposure to shorter UV light can cause very serious problems (such as cataract). This is a different mechanism that just sheer power which is normally associated with lasers - i guess you could compare it to sunburn.

On the positive side, most 'uv' leds are around 400 nm, perhaps down to 385 or so. At that wavelength the risks are rather limited, but if you go towards 350 nm be careful.
 

Razako

0
Joined
Mar 17, 2006
Messages
4,301
Points
113
Some guy on dx says that the light from this is 395nm. I'm not sure how reliable some random guy on dx is and also it might vary from diode to diode. I'm also a bit annoyed because I was told that this can be used to detect pet urine and blood and this light seems to fail at detecting both of them.
 
Joined
Sep 22, 2007
Messages
977
Points
0
It detects those things just fine if you use the chemicals that bind to the heme group in blood and specific proteins in urine. Forensic technicians don't spray luminol all over for nothing.
 

MERC

0
Joined
Dec 18, 2007
Messages
132
Points
18
It should work fine for detecting urine, I rigged somthing like that up and i can see urine glow(works best on dry urine).
 

Switch

0
Joined
Dec 9, 2007
Messages
3,327
Points
0
Yea , they're supposed to be 395nm, but all the POS cheapies are probably over 400nm....the violet you see is no bleed, it's the actual peak wavelength.Filtering that out will eliminate all fluorescence :( :p

My eyes tend to hurt from a blacklight tube too.Don't know about LEDs cause I only have a LED keychain that is not really powerful and I thought it was best not to shine it in my eyes for several minutes :D
 

diachi

0
Joined
Feb 22, 2008
Messages
9,700
Points
113
ive never noticed anything with my Blacklight that i have, and ive spent 5-10 minutes looking right at it playing with paper and high lighters, or maybe they do and i dont noticew it cause they're already sore from lack of sleep :-/

but you should be ok anyway doubt it will cause any perminant damage
 
Joined
Nov 2, 2007
Messages
536
Points
18
UV-Violet leds never go under 365nm. Research labs has made LEDs emmiting light in the 300nm region but lasted less than 10 seconds.
 




Top