LED light and eye health

Roen

In the pursuit of all manner of lighting trickery are we inadvertently putting our eye health at risk?

Heard second hand from an industrial lighting specialist that if you use LEDs you should mix in older light sources too as the light from LED can cause eye strain.

Far from expert myself on this subject but the main areas of concern seem to be CRI, flicker and waveform.

You'd like to think that for the price you pay for 'smart' bulbs that you'd be ok. Cheap Ikea and generic ebay/amazon stuff maybe not so much.

I guess lighting is one of those things people take for granted and will pick up the cheapest bulbs they can get.

Interesting articles here.

http://www.archlighting.com/technology/leds-fighting-flicker_o
http://www.ledbenchmark.com/faq/LED-Flicker-Measurement.html

Anyone up on the subject able to chime in?
R.

Arbie

Roen wrote: »

In the pursuit of all manner of lighting trickery are we inadvertently putting our eye health at risk?

Heard second hand from an industrial lighting specialist that if you use LEDs you should mix in older light sources too as the light from LED can cause eye strain.

Far from expert myself on this subject but the main areas of concern seem to be CRI, flicker and waveform.

You'd like to think that for the price you pay for 'smart' bulbs that you'd be ok. Cheap Ikea and generic ebay/amazon stuff maybe not so much.

I guess lighting is one of those things people take for granted and will pick up the cheapest bulbs they can get.

Interesting articles here.

http://www.archlighting.com/technology/leds-fighting-flicker_o
http://www.ledbenchmark.com/faq/LED-Flicker-Measurement.html

Anyone up on the subject able to chime in?
R.

There is no evidence that new lighting technology does any harm to eyes. Our eyes are resilient and remarkably evolved to work well in different environments with wide variations in light intensity, colour, etc.

Eye strain is a vague term but in medicine it refers to aesthenopia. Sustained flicker at lower Hz can cause strain. Suggestions of effects at higher Hz are dubious. Old cathode ray tubes (i.e. every TV/display until about 10 years ago) and CFLs were far worse for this than LCDs/LEDs, so if anything new technology is better for eyes! Avoid cheap CFLs.

The biggest cause of eye strain is people doing close work on bright screens for very long periods without a break, particularly if this is in a dim room. This can lead to eye strain, dry eye, headache, even nausea, but no long term harm. Anyone doing a lot of close work should follow the 20/20/20 rule: take a break every 20 minutes for 20 seconds and look at something 20 feet away.

Stoner

Roen wrote:

Far from expert myself on this subject but the main areas of concern seem to be CRI, flicker and waveform.

It can be the Coating or lack of on the lamps, so white or cold blue LEDs are brighter but potentially a risk


http://ehp.niehs.nih.gov/122-a81/

Arbie

Stoner wrote: »

It can be the Coating or lack of on the lamps, so white or cold blue LEDs are brighter but potentially a risk


http://ehp.niehs.nih.gov/122-a81/

That paper is flawed and doesn't reflect either the latest research or a consensus on the issue. They used rats, which are not a good model for primates. They are albino rats, which means they are far more susceptible to retinal damage. The study didn't include incandescent lights for comparison. They lit the rats at night time, which is their active time, totally reversing their light:dark circadian cycle which can lead to the very oxidative stresses that the researchers were supposed to be measuring. From those ERGs it looks like the rats exposed to both white and yellow CFLs would be severely visually impaired. If that held true for humans we would know about it by now.

The current expert view is that the negative animal results are weak and LEDs are safe.