In general, lcd crystal displays are back light with white light. Older displays used flourescent light while the newer one use white light leds. There are newer and more expensive lcds that use red, green, & blue leds to make white light.
With over 150 millions iPads sold, negative news stories would be all over the news.
consult your optomistrist.
Apple devices use the same display and illumination technologies used in all other popular devices of the same kind produced by Samsung, LG, Sony, Microsoft, etc.. They're made by the same companies in the same factories using the same equipment. I can show you psysiology studies that show neuroactivation curves generated by the backlights used in these devices but currently nobody seems to feel that they're dangerous in any way.
Also worth noting that walking around in the sun at noon, even on a cloudy day, provides at least 15 times the amount of illumination at all frequencies than electronic devices put out. You should be far more concerned about the light put out by the sun at noon on a hot day.
There are some reports which suggest that exposing yourself to blue-tinged light late at night will delay your body-clock and make it harder to get to sleep. These are not proper scientific peer-reviewed studies with blind testing and control groups, but there's no reason to doubt the reports. If this worries you (and it probably shouldn't) and you find that using devices late at night prevents you from getting to sleep, then I recommend you buy some cheap orange-shaded sunglasses, or some cheap orange translucent film to put over the displays.
The answer is probably and not just Apple, but any LED (including LED bulbs).
However screens probably cause more damage because you look at the light as opposed to viewing reflected light from light bulbs.
It is all to do with light becoming more damaging as you get closer to the blue ultra-violet part of the visible light spectrum. In this case we are talking about blue light which is quite close to UV and is abundant in LED light.
What can you do. I visited the eye clinic last week, beacuse of dry eyes, their view is that they are getting such a large number of cased compared to a few years back that they are certain that increased screen use is to blame.
Of course they can not know for sure and by the time we know for sure it will probably be too late for the majority of us.
Funnily enough they suggested (and provided me with) blue filter glasses (I wear reading glasses so my new prescription has blue filter), though they come with a disclaimer as to their efficacy (i.e. lack of it) at preventing any type of eye damage.
Excuse me if I posted a bad link, there are dozens of articles on the internet
Many from reputable newspapers such as the Daily Mail
Her comments are partly based on her 2012 study that was published in the journal Photochemistry and Photobiology.
The study found that LED radiation caused significant damage to human retinal pigment epithelial cells in vitro.
Sánchez-Ramos added that modern humans have their eyes open for roughly 6,000 hours a year, and are exposed to artificial light for the majority of that time.
Some experts have called for the LED lights to have built-in filters to cut out the blue glare.
There are no doubt arguments on both sides as their was with tobacco and passive smoking, climate change, as well as other things suspected to have 'long term' effects, that are difficult to measure over the short term.
As I said in my post, you won't know who is right until it is too late. Most of my comments are due to the conversation I had with the consultant (and two other junior eye doctors) last week at the clinic. They have not done any research nor have they collated any statistical study, but their judgement is that they are seeing a lot more cases of eye problems and they believe (albeight without any data) that screens are a culprit. Of course they will have cognitive biases (there is an increase in screen usage, so they will see more screen users than 5 years ago, and humans tend to link things that occur at the same time and sometimes they have common/related cause and sometimes they don't.)
Sorry, but 'reputable' and Daily Mail should not be used in close proximity.
I won't talk about the other things you wrote, but the Daily Mail's job is to sell newspapers, and the best way to do that is to publish big life-effecting claims for its readers to worry about. Its main tactic seems to be an attempt to partition everything into the world into things that cause cancer and things that cure cancer (credit: Marcus Brigstocke) and the other things it does aren't very sensible either.
They have not done any research nor have they collated any statistical study
That's enough said right there. They observe an effect and make a snap judgement on the cause with no evidence, just guesswork. That's equivalent to the old joke about the guy who bangs a pan all day, and when asked why he does it, says "to keep elephants away". When told "there aren't any elephants around here", the guy replies "see, it works".
As to the study by Dr. Ramos, without being able to read the entire study, I can't comment, but see:
Dr. Ramos' study may well be valid and worth further investigation, but a single study based on non-real-world conditions is no cause for panic. But you are free to take whatever precautions you feel appropriate. But I would suggest that if you are worried about the effect of blue light on your eyes, you avoid going into any room painted blue or containing a significant amount of blue furniture, avoid looking at any object that is predominantly blue, and avoid going outside for significant periods of time except when the sky is overcast.