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iPhone X FaceID and eye safety
- Thread starter stafil
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At which point your iris allows 15 times less light to reach the retina.
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Face ID *does* work in direct sunlight though. It might occasionally throw it off, but if it didn't work at all you'd be hearing a lot more about that problem. In my own experience it works fine in sunlight. Which tells me that the concentrated points of IR light projected across your face by Face ID are obviously stronger than the diffuse IR from the sun.
Of course it's different. It's probably 'concentrated' into small dots, all at one wavelength, and those dots probably flash. So what? You cannot hold the phone still enough to stop the dots moving around. The dots are not intense enough to affect you even if they were held perfectly still. Whether the IR comes from a laser or a lamp or the sun makes no difference. All that matters is average intensity, where the sun obviously puts FaceID to shame.
Have you ever used an IR TV remote control?
I've already dealt with this. We don't know what wavelength FaceID operates at. If it is near-IR, then much-to-most is absorbed by the cornea. If it is not very-near-IR, then all is absorbed by the cornea.
Of course the intensity matters. Are you serious? A laser is very different from a diffuse light source. And yes I have used an IR remote; no, I have not made a habit of beaming thousands of them into my face and eyes over a hundred times a day. I also find the lack of information troubling. As you yourself pointed out, we don’t really know any details about the wavelength or intensity being used. We just have to trust Apple.
https://forums.macrumors.com/threads/faceid-analysis.2153432/
I owe you an apology. I was completely wrong when I predicted low emitting power in nW. We did quite some testing, so I opened a new thread.
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This is not entirely true. Up until 950 the absorption in water is quite low. Though I agree that anything beyond 1200nm is most probably completely absorbed in either cornea, lens or the vitreous body before reaching retina.
A laser is not a bogeyman. It's not evil and damaging just because it's a laser. A 0.1 mW/cm^2 laser is likely to be less dangerous than a 0.1 mW/cm^2 diffuse light source, as the spot of the laser will wander around instead of illuminating the exact same spot constantly.
Some people here seem to think that FaceID detects your retinas, and shines blindingly powerful IR directly into them. That is frankly ludicrous.
As I have already stated in this thread, Class 1 lasers are considered always eye safe, and have a maximum power of 1 mW. That is PER BEAM. FaceID projects over 30,000 dots. Some simple maths shows that if each beam was at the upper limit of Class 1, it would draw over 30W, plus losses due to inefficiencies. It obviously does not, as that would destroy battery life, and would likely burn out the FaceID sensor. And to say it again, even in that extreme example, that battery destroying FaceID would still be eye safe.
You do not need to 'trust Apple'. You just need to trust the certification process.
I didn't say that. I said there's a difference between diffuse IR radiation and an IR laser.
I didn't say that either.
They're not considered always eye safe, because they always come with safety warnings about proper use. The iPhone TrueDepth system deactivates itself if it detects tampering or malfunction, obviously because it has the potential to be dangerous when it's not operating normally.
In any case, where are the long-term epidemiological studies investigating the effects of shining 30,000 of them across your face a hundred times per day for a decade? There aren't any, simple as that. I'm not saying Face ID is harmful, I'm saying we don't know for sure. Even a cursory examination of the history of the pharmaceutical and tech industries will show that regulations are often insufficient to protect consumers, particularly when there's a lack of long-term studies. I'd say caution is warranted, that's all.
I believe it's clearly implied from your arguments.
That's an assumption. Even if it is true, it's irrelevant. We are till talking about something that operates at powers far (as in likely multiple orders of magnitude) below the threshold that the studies and guidelines accept are safe. Also the guidelines include a healthy factor of safety.
I'd say caution is warranted if there was any potential logical link that would cause harm. But as I have said over and over again, if FaceID was intense enough to cause damage, it would decimate battery life. It would also noticeably warm your face. Our skin is exposed to comparatively huge amounts of IR every time we go outside, to no ill effects (UV is damaging).
There are studies that investigate IR intensities and durations that can cause damage. These have already been mentioned in this thread. They reinforce the fact that damaging levels of IR radiation would manifest in a lot of power drain.
One final note, someone out there (likely dozens or hundreds of people) who has access to the equipment to analyse power density and wavelength of FaceID will have bought an X, Xs or Xr, and tested it just because they could. The equipment would exist in some businesses, a lot of universities, plus in the homes of some. If they had found it had even the slightest possibility of being dangerous, it would be all over the news. We are also a full year into its operation (specifically for FaceID, much longer for other implementations), no problems yet.
FWIW, YMMV, I get a prickling / tickling sensation on the face every time I use the clips app or Animoji with in a few seconds. :shrug:
"Safe" is relative term. What do you define as safe? When would you feel that it's unsafe?
"Safe" is relative term. What do you define as safe? When would you feel that it's unsafe?
Here is a simple test you can do without great expense. Cover the emitters with black tape. Use the phone, if you still have eye pain it’s not from infrared. Most likely from OLED screen. There are some people sensitive to the 250 Hz refresh rate.
Conversely you can cover screen and leave emitters open to flash your face and stare at phone for several hours.
Then if you truelly want to be scientific, stare at back of phone for some hours as a control.
There are many reasons for your eye pain. You have decided, without experimentation, the source of your eye pain. Then re-enforced your opinion by repeating your opinion.
There is a segment of population that is of the opinion the earth is flat. The fact that they are wrong, bares not sway to their opinion.
Opinions are detrimental to the scientific method of seeking facts.
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If 30,000 laser dots are flashed across your face. How is the dots hitting your chin affect your eye? At most a dozen or so dots go into the cornea.
Have you ever considered it's all in your head? You expect it to affect you, so it 'affects' you. It's called the nocebo effect.
Either causing noticeable short-term damage, or any damage which is not fully repaired and accumulates.
Comparing me with a flat-earther doesn't help your case or makes you worth my time to reply to you. I would suggest you refrain from such characterizations in the future if you are expecting a reply.
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You are wasting your time. People are unwilling to look further than their tiny bubble. If they don't have symptoms, then they don't believe yours and call it "placebo".
In another thread user "537635" actually measured the power of the Flood Illuminator and the Dot Projector. They are safe, as in within the safe limits specified by various bodies. The results say that, based on our current knowledge and studies, FaceID will *not* cause any short or long term health effects.
However I do know that it causes my eye-balls to hurt (covering everything with black-tape makes the pain go away), and I do believe you that you have the prickling/tickling sensation. Why is that I don't know, and it's unlikely to find out by ourselves.
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You and your friends have come up with a conspiracy theory. You are suggesting that Apple can't be trusted, AND the impartial certification & safety processes can't be trusted. Not only that, you are suggesting that the studies that have been done that show that it is safe, can't be trusted either.
Then, based on your conspiracy theory, you spread fear and doubt. When you are challenged, you expect others to prove that FaceID is safe, assumedly without relying on any of the existing factors and evidence that shows it is safe that you have already discounted. It therefore be likely that if some third-party did do the research, you would reject that too.
Placebo and Nocebo are well documented and researched, real and strong effects. There is no shame in being affected by this phenomena. Most people are.
To put it simply, I think Occam's Razor clearly applies here. There could be a widespread conspiracy, plus an unknown mechanism by which FaceID would be harmful, against known medical research. Or, some people could be affected by Nocebo, after reading the unjustified fear mongering online. The correct answer is clear.
I don’t know why you make it personal or what your problem is. I clearly said it shouldn’t cause any issues based on another user’s measurments. Did you even read this:
“In another thread user "537635" actually measured the power of the Flood Illuminator and the Dot Projector. They are safe, as in within the safe limits specified by various bodies. The results say that, based on our current knowledge and studies, FaceID will *not* cause any short or long term health effects.”
Also if you bother to read my replies to people who ask if they should disable it or even not buy the phone, I always tell them they shouldn’t worry and it shouldn’t affect them as it affects a very tiny percentage.
Really not sure what problem you have, but you need to let it go.
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Sorry cannot read all the pages, can someone please a summary of conclusion or is it still in debate ?
There is no health safety issue to worry about.
A user from the forum was kind enough to measure it himself. See:
https://forums.macrumors.com/threads/faceid-analysis.2153432/
Why some small number of people get symptoms is unknown but nothing to worry about.
Firstly, I don’t know if you are a flat-earther or not. Any comparison you perceive is within your own mind, not mine. As to making my case, you are making it for me. Pointing out the lack of evidence along with rejection of contrary evidence and experimentation shown by proponents of other wild conjectures seems quite fitting in this situation. Opinions have no bearing on the validity or causality of your eye problem.
This refrain reminds me of the writings of Moliere regarding 17th century physicians who would meet and discuss the ailments of a patient without examining the patient or conducting any tests. Once the learned doctors would agree upon a course of treatment, based on the age and reputation of the senior physician. Treatment would commence by some underling. Often as not, the treatment was deemed successful regardless if the patient survived.
As to expecting a reply from you, to be perfectly honest, I did not expect or desire one. I was actually addressing, more so, the other respondents to the post. Offering a methodology you might entertain to actually discover or rule out the actual source of your eye issues, seems to have fallen on deaf ears.
In conclusion and to be perfectly clear, no reply is expected.
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I will just copy&paste this here: Before I dismissed these concerns as utterly irrelevant and paranoid. Now I'm leaning more towards "most probably OK for normal use, but don't put your phone next to your eye".
I have to admit I was a bit surprised by the energy levels of the IR emitters in FaceID. Again, most probably safe, but not at all at the levels, where you would dismiss everything as paranoid. It's still a couple of milliwatts. Exacerbated by the fact that it is near-infrared, which means you never know what hit you.
Example: Green lasers are notorious for being most destructive in terms of eye safety. But the thing is, you will notice it immediately and switch it off or remove yourself from the room. Near-IR on the other hand can cause silent damage on the retina, which is visible only on a very sophisticated ophthalmological exam (perimetry). I have these exams every two years and each time I get a little paranoid.
When looked upon in the dark and with an IR camera, the flood illuminator and dot projector are blindingly bright. The animations I did were recorded with an old iPhone, which partly filters the IR light.
Bottom line: I don't believe it's completely black and white. I'm still using faceID, which means I do not believe it is more dangerous compared to other stuff (like driving a car). One of my colleagues actually said: "Wow, this would never fly with our safety audit."
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Does this tape block IR or is it that you just don't notice the flash but the tape still lets IR pass through? Some XR users also mention about eye strain and since it uses LCD with no PWM as per Notebookcheck review, it could be something which is common in X, XS and XR and not previous gen 7 & 8. That points to some component in the FaceID system.
It's like walking through airport security X-ray scanners, it doesn't cause any major issues if you pass through once or twice but if you are a frequent flier then it's better if there is data available showing if and how X-rays affect and what precautions you need to take.
A small number of people seem to notice eye strain and it could be worth looking into... for everyone's safety. If it turns out to be no health issues then well and good, we don't lose anything by having it backed up by data.
[doublepost=1542002950][/doublepost]Has Apple published any testing results to confirm that FaceID or PWM doesn't have any health implications after prolonged usage?
It's like walking through airport security X-ray scanners, it doesn't cause any major issues if you pass through once or twice but if you are a frequent flier then it's better if there is data available showing if and how X-rays affect and what precautions you need to take.
A small number of people seem to notice eye strain and it could be worth looking into... for everyone's safety. If it turns out to be no health issues then well and good, we don't lose anything by having it backed up by data.
Black tape will block 99+% of IR light. The remainder will get completely scattered.
On airports there are NO x-ray scanners humans would pass through. Luggage scanners are x-ray (next time notice the thick lead rubber double curtains where luggage is going in or out), body scanners are radiowaves (the thing where you raise your hands), traditional scanners (looks like a door frame) are passive EM scanners (as in they do not emit anything).
It's nice how you quote one paragraph of what you said, and omit the following paragraph. The one where you contradict those findings, and claim that it hurts you. My only "problem" here is that people continue to spread fear and uncertainty that FaceID can be damaging or painful, without any scientific basis. As I have outlined previously, Apple have already sufficiently shown that it is safe, otherwise it would not be able to be sold. The onus is therefore on you to prove they are incorrect.
As for the "make it personal" business, when one is talking to another, it usually occurs on a personalised basis.
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If there was some scientific basis for this being potentially dangerous, then they would be expected to. FaceID bathes your face in IR light, but your face is always being bathed in IR light at much higher intensities, especially if you go outside, or have ever been in a room with an incandescent light globe. Same goes for PWM. CRT screens flash at comparatively low frequencies, and have been used around the world, every day for hours, by many people. They have recently been replaced, but not for safety reasons. Fluorescent lights flash at very high frequencies, and again are around us for hours and hours every day. If there was some legitimate reason as to why PWM screens and FaceID were different to these other technologies which have been proven safe through the test of time, then fine, investigate away. But they haven't.
The difference is that x-rays have a clear scientific basis for being damaging. They can damage DNA, and that damage will accumulate. There is no such link for low intensity IR or PWM.
By far the most logical answer is 'nocebo'. There is no harm in a covertly conducted, independent study into the health effects. However there is harm in conducting a public 'trial-by-opinion', like is happening now. It will set back safe, technological progress, and will colour any potential future independent studies, as people will have difficulty staying impartial.
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Thank you for taking the time to do these experiments, and get some hard numbers. However, for me it comes down to the fact that your measured powers are on the order of 1.5mW, measured over 4cm^2, barely 2 inches from the emitter. Following those numbers through, with say a highly dilated 8mm pupil, held at a very close distance of 6in, you're looking at peak power of single-digit micro-watts. i.e over 2 orders of magnitude lower than safe levels.