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It's probably just the fact that it's a very localised bright source that's affecting her. What happens if you screen it from her direct view? Any pulsing would still be present in the reflected light.

Sylvia.

Hello Sylvia,

The reflected light still causes her pain in the eyes. I was screening her from directly viewing the LEDs themselves, and she was looking away from the source when she first told me it was causing her pain. I have since found that the LEDs give off a bluish-white light, somewhat similar to the headlights of some newer cars that also drive her crazy. Am hoping that filtering the light might help...

Thanks for the input,

Dave

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I have the same trouble with a headband type light i bought. I think its just the color of the light. I cant tolerate blue headlights either. I think part of it because my iris does not adjust in response to the light.

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You don't need any fancy equipment or circuitry to see if it's pulsing. Turn it on and wave it back and forth in a darkened room very quickly. If it's not constant it will be very obvious. If you're not sure that it isn't pulsing too fast for you to see, try illuminating a fan in a darkened room (strobe effect). If the fan doesn't appear to freeze, change speed, or run backwards the LED is not pulsing.

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Looks like a viewing angle graph. The spec claims: "View(to my eyeball, anyway).

I'm guessing your XYL is just sensitive to very bright bluish light sources. For diffusion purposes try what the pros use, "frosted" clear plastic of whatever kind is handy. If you used a piece of acrylic or whatever as a cover, go over it with 60 or so grit sandpaper. I can't think of much you can do about the color though.

Mark L. Fergerson

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interseting.. my XYL objects to the LED under kitchen cabinet lights i am trying to gin up.

I see it as two issues,

2) the color needs to be warm... I think you can get around this one by combining a "WHITE" LED and a "YELLOW" or "ORANGE" LED.. I have already seen this done commercially.

Mark

Don't know about your wifes sensitivity, but here's an article I found interesting about how the eye reacts to different temperature lighting. Read about how light temp affects the pupil.

Hey Mike,

THANK YOU for that wonderful article, and website link. Saved it as a favorite, as I expect to be talking with them soon about this issue. Much appreciated.

Dave

interseting.. my XYL objects to the LED under kitchen cabinet lights i am trying to gin up.

I see it as two issues,

2) the color needs to be warm... I think you can get around this one by combining a "WHITE" LED and a "YELLOW" or "ORANGE" LED.. I have already seen this done commercially.

Mark

Hey Mark,

Thank you for these ideas. I can see them coming in very handy. Could easily add colored LEDs to my lantern if it would help...

Dave

I will attempt to discover which campus and building they conducted this experiment in. I work at Intel in Hillsboro, but there is no "Hillsboro Campus" there are 6 of them totaling more than 50 buildings. If I can find the location I'll go and see it for myself (and interview some of the people who work in the area.)

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What the heck happened there? That should have read:

'Looks like a viewing angle graph. The spec claims:

"Viewing Angle 2=E81/2 Typ. 120=B0"

The included angle on the graph eyeballs about that (to my eyeball, anyway).'

Mark L. Fergerson

Yes Dave, Very useful information. I was looking to help my mother see her computer screen better. She has cateracts and I thought shrinking down the pupil would help with reflections within the eye. I didn't get to make use of the info for her, I'm 1000 miles away and couldn't get follow up on her end. I did get myself a couple of high temp lights though. Mike PS. It looks to me like those LEDs are 9000K? That doesn't even show up in the info on that page IIRC.

Is your mother in the US? On Medicare? A lens replacement treatment of cataracts is free. I have one.

...Jim Thompson

Yes, IIRC the info on that page only goes up to 7500K. Makes me think the LED in question is likely emitting very high frequency but invisible light, which the iris won't respond too but which will still affect the retina. Did some more research on articles referrenced by Wikipedia and honestly got a little scared that I might have permanently damaged her eyes, as she says they *still* hurt. Man oh man. What have I done? Going to see if she feels a visit to the eye doctor is in order.

Dave

Yes Jim, In fact she had one eye done, and when she saw the doctors office billed Medicare between $4000 and $7000 (I don't recall the exact amount ) she said she would not get the other one done. She said the whole procedure was less then 2 hours including her time in the waiting room. She thinks that's ridiculous! Maybe I should tell her "If Harry Reid can have a billion dollar high speed train, it's ok for you to have a few thousand dollar cataract removal. Mike And Jim, I known you don't really believe it's free.

Well! Considering what I paid in over the years... free? No! But I'm getting back 5¢ on the dollar... better than Madoff investors ;-)

...Jim Thompson

There are "white" LEDs with color temp. getting to 9,000 K or so but emitting close to no UV at all. They just emit a somewhat disproportionately high amount of visible blue (mostly in wavelengths that are blue/bluish but longer than 440 nm), and a disproportionately lower amount of red and slightly disproportionately lower amount of mid-green. They emit little infrared - what is radiated is mainly visible light, fair chance around or over 90% of radiation at wavelengths less than 3 micrometers is in the range of 430 to 680 nanometers for white/bluish-white LEDs with correlated color temp. 6,000 to 15,000 K.

- Don Klipstein ( snipped-for-privacy@misty.com)

I can't figure out the couple of guys that commited suicide over the Madoff scheme, It seems to me they took out the wrong guy. Mike

Why thank you, Don. This is likely what I am dealing with then. And it is the bluish light that is driving her crazy. Do you suppose that he lenses from Blublockers sunglasses might help with that? I am not sure what else to try.

Much appreciated.

Dave

I don't like the blues at all. I bought a bunch of Luxeon III's that are warm white which I was going to install under the kitchen cabs, and other uses. The blues are cheaper. Thats why they are popular.

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