http://www.bbc.co.uk/news/health-30574260

I'd be looking a bigger study, plus most of those devices mentioned weren't designed as e-readers.

I read on my Kindle for a bit when I go to bed and I fall asleep quite quickly.

I've got the Voyage's brightness ramped up and I'm the same.

No doubt they'll find a similar result if they measured against people who watch TV just before sleep.

Go and do some proper research.

+1 for larger study. 12 people is ridiculously small. But similar studies in the past with smartphones/tablets have shown similar results IIRC.

All comes down to sleep hygiene, which is what this study really is about.

Plus, the report talks about eBook readers, then goes on to list the iPad (not an eReader), the Kindle Fire (not an eReader) and the Nook (which, going by the other 2 devices, is probably the tablet version and not the eBook Reader version).

It would be interesting if they had been given an actual eReader (such as the Kindle Paperwhite, Tolino, Sony etc.).

The study was done using backlit ereaders. The tablet/smartphone/TV was an extrapolation of this. I don't recall specific brands being mentioned.

The report said that they read a paper book for the first half of the test and an iPad for the second half. That is not an eReader, that is a tablet...

I read the paper and not the BBC report. It mentions a backlit e reader throughout and then in small print in the methods section it mentions reading an LE-eBook (iPad; Apple Inc., Cupertino, CA)

I find it mega annoying since e reader=/= ipad. Moreover they used the maximum brightness! I use the kindle app on my iPhone and have it inverted ie black background white text and brightness reduced.

The exact kit used is less important than the fundamental biological mechanism they're studying. It could be any tablet or even quite a lot of e-readers that now use significant backlighting, as oppose to the initial generation that just used ambient light reflection. I doubt the light coming off a Kindle Voyage is actually that different to an iPad, frankly.

The basic point seems fairly reasonable - exposing yourself to bright lights just before sleeping upsets your body's sleep cycle timing. I don't think anyone would argue that is somehow outlandish and obviously impossible.

The study is small but the results were statistically significant, even with the small subject group. That doesn't suggest a definitive relationship, but it does suggest there's something there worthy of further study.

Except the eReader makers explicitly state that they use a different LED that doesn't give off blue light / so much blue light as a normal tablet display with backlight.

That is why I would be interested if they had actually used a real eReader.

Do they? Got a reference, sadly Google searches are now flooded with articles about this story, so I can't find anything useful to that end.

I'd expect them to want to get as close to the reflected light you get from paper as possible for aesthetic reasons, but I'd expect it to only make a small difference in the overall effect. Non-backlit to be the best option by a mile, basically.

Amazon certainly stated that the LED is reader friendly, unlike normal backlighting on tablets.

Okay, it looks like it is because it is projected at the screen from above, away from the reader's eyes, that it is better for you. It doesn't project blue light at you, it lights the display, so is no worse than reading a paper book with an LED bedside lamp.

So front lit onto the reflective back layer of the e-paper display, rather than the display actually being luminescent of itself? That makes some kind of sense. In theory you could make an reader app for tablets that uses a background colour that emits less of the blue light but I suspect the normal reader apps just use white (or as near as tablets can get to actual white). The academic I heard being interviewed about the study said the best option was to invert the display if you could, so the majority of it was black(ish). That seemed a sensible measure.