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Thread: Cheap sunglasses and UV LEDS

  1. #1
    Unenlightened
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    Jan 2002
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    Default Cheap sunglasses and UV LEDS

    It's kind of satisfying to have $5 imitation Oakley sunglasses that I bought from a street vendor in Bangkok but I'm interested to see how well they protect against UV light. I thought I could get a UV LED and shine it through my proper sunglasses onto something fluorescent and compare it to the brightness from shining through the imitation sunglasses for a crude idea of the UV protection.

    I tried it with my 1W blue Luxeon Star shining on a Princeton Tech 40 and I can't see any difference in its fluorescence. I was wondering if there is a more suitable UV LED I can try?

  2. #2
    Flashaholic* LED_ASAP's Avatar
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    Default Re: Cheap sunglasses and UV LEDS

    Why don't you compare a pair of trusted (and expensive) sunglasses and see if your cheap deal is actually doing anything.

  3. #3
    Flashaholic* Quickbeam's Avatar
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    Default Re: Cheap sunglasses and UV LEDS

    Blue luxeons don't emit UV. They are high enough frequency to make fluorescent materials glow, but it doesn't take UV to do that. Shine it on a visa or amex creditcard. If a light emits UV, the Amex will have a big AMEX glow over the entire face of the card. Visa should have a big dove appear that you can't see in normal light. I'll try to take a pic to demonstrate.

    Here you go:


    BTW, my glasses are UV resisitant, but UV fluorescing compounds glow even if I shine the UV through the lenses... A science teacher told me that UV resistant lenses block UVA but not UVB or vice versa. Can't remember which.

  4. #4

    Default Re: Cheap sunglasses and UV LEDS

    [ QUOTE ]
    LED mods As Small As Possible said:
    Why don't you compare a pair of trusted (and expensive) sunglasses and see if your cheap deal is actually doing anything.

    [/ QUOTE ]

    You never know, you may be surprised. Let's face it: most of the time 90% of the price you pay for any big name brand is for the name, not the item itself. Let us know what happens, it would be interesting to find out.

  5. #5
    Flashaholic*
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    Default Re: Cheap sunglasses and UV LEDS

    Along these lines... I wear prescription lenses, and they're supposed to block 99% of UV. I find that when I'm in a nightclub or other area with a lot of blacklight, the lenses "fog up" - something in the lens itself starts to fluoresce. Very annoying.

  6. #6
    Flashaholic* RonM's Avatar
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    Default Re: Cheap sunglasses and UV LEDS

    High priced sunglass makers used to prey on the consumers worries about UV protection. That was until it some independent testing showed that virtually all sunglasses do a good job of blocking UV. $150 Oakleys or 2 for $15 glasses from the kiosk at the mall, it just doesn't matter. [img]/ubbthreads/images/graemlins/cool.gif[/img]

  7. #7

    Default Re: Cheap sunglasses and UV LEDS

    [ QUOTE ]
    highlandsun said:
    ...I find that when I'm in a nightclub or other area with a lot of blacklight, the lenses "fog up" - something in the lens itself starts to fluoresce. Very annoying.

    [/ QUOTE ]

    Just wondering... might that be the way they "block" UV, by absorbing and re-emitting it on a different wavelength ?

  8. #8
    Flashaholic*
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    Default Re: Cheap sunglasses and UV LEDS

    Makes sense... The energy has to go somewhere, I suppose. Maybe I should take comfort in the fact that I know the UV block is doing its job...

  9. #9
    Flashaholic
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    Default Re: Cheap sunglasses and UV LEDS

    According to a salesman for Briko (a friend), there isn't much difference in the lens material at all. It seems that there are only three major mills that make the plactic and polish it. This doesn't include the real premium makers like Nikon or B&L who use custom manufactured "cast" lenses. These mostly make the lenses in their own factories, but it does include the "second tier" volume manufactures like Briko, Oakly and the like. There are difference is in the polish and tint, but not as much as you would think and certainly not enough to warrant the cost difference.

    I own quite a few pairs of cycling glasses including Nikin, B&L, Oakly, Briko as well as a number of Tiwan or China clones and I can say from personal use that, for the most part the clones are perfectly satisfactory. When riding I generally use a clone pair. The mechanical build may not be quite as good, but the "real world" difference is slight.

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