Looking for special sunglasses...

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Dave - 15 Feb 2009 04:19 GMT

Trying to find some "wear-overs" or wrap-around sunglasses that block all
UV-A and UV-B light, to filter out the high frequency end of light emitted
by some ultra-bright LEDs I found. They light up great, but hurt my wife's
eyes. Documented as having a CCT (think that's right) of 9000K (know that
is right, believe it or not.) Suspect her eye pain is caused by
high-frequency and invisible light to which her iris does not respond. Am
hoping that said sunglasses, maybe doubled, will filter out said
high-frequency light.

Thanks,

Dave

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Mike Tyner - 15 Feb 2009 17:19 GMT

> by some ultra-bright LEDs I found. They light up great, but hurt my
> wife's eyes. Documented as having a CCT (think that's right) of 9000K
> (know that

Wouldn't assume there's a huge load of UV delivered to the eye. Color temp
may not mean what you think it means.

9000 kelvins is decribed as "blue" on color temp charts. The fact that
"9000" exists as a point on a printable color temperature map places it in
the _visible_ range. The chart at
http://www.cameraguild.com/technology/kelvin.htm shows the deepest blue as
28,000K ("North sky" blue).

Then, LEDs are notoriously wimpy, at any color temp. And intensity
diminishes as the square of distance.

If you wore your LEDs next to your skin for a couple of hours, I doubt you'd
see sunburn.

-MT, OD

> Trying to find some "wear-overs" or wrap-around sunglasses that block all
> UV-A and UV-B light, to filter out the high frequency end of light emitted
[quoted text clipped - 8 lines]
>
> Dave

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Dave - 16 Feb 2009 13:28 GMT

>> by some ultra-bright LEDs I found. They light up great, but hurt my
>> wife's eyes. Documented as having a CCT (think that's right) of 9000K
[quoted text clipped - 16 lines]
>
> -MT, OD

Hey Mike, thanks for the reply.

Wow. Thank you for that link. 28000K. Man, I had no idea. Still, they
hurt her eyes, and left them hurting for quite a while. I am hoping to find
something that filters out some of the high-end blue light to see if that
helps. Blublckers, if nothing else...

These LEDs are rated at 660 mW, by the way, and are incredibly bright.
Bright enough that I built an emergency lantern out of (two of) them. Only
I can't use it in it's current configuration.

Thanks again,

Dave

>> Trying to find some "wear-overs" or wrap-around sunglasses that block all
>> UV-A and UV-B light, to filter out the high frequency end of light
[quoted text clipped - 8 lines]
>>
>> Dave

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Dave - 17 Feb 2009 13:08 GMT

>>> by some ultra-bright LEDs I found. They light up great, but hurt my
>>> wife's eyes. Documented as having a CCT (think that's right) of 9000K
[quoted text clipped - 44 lines]
>>>
>>> Dave

Okay, wife got tired of hearing about this and decided to join in on
figuring out a way to make it work so I would shut up about it. She
suggested parchment paper as a diffuser. I cut the bottom out of a plastic
bottle, wrapped parchment paper around/over it, and taped this in place as a
sort of lamp shade. It works. Minimal reduction of light, and no glaring
"blue-white" light. Damn thing gives off light like a 40-watt bulb, which
doesn't sound like much but in the dark it is incredible (for two LEDs). It
now sets on the shelf in the study, waiting for the lights to go out. Damn.
Don't know what else to say. I married a smart woman. :)

Best,

Dave

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Mike Tyner - 17 Feb 2009 22:57 GMT

The luminous efficacy of LEDs ranges from 10 to 100 lm/watt.

Your 1.3 watts might translate to about 500-1000 lumens, same range as a 60
or 100-watt incandescent.

Pretty intense when expressed in lumens per degree.

-MT

>>>> by some ultra-bright LEDs I found. They light up great, but hurt my
>>>> wife's eyes. Documented as having a CCT (think that's right) of 9000K
[quoted text clipped - 59 lines]
>
> Dave

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