Migraines from high-frequency flicker (above normal fusion rate)
December 18, 2017 5:58 PM Subscribe
My office moved locations recently, into somewhere which has been refitted with some surprisingly white and bright LED panels on the ceiling. These have a flicker on them which I can't see directly, but causes me eyestrain fairly fast, and nausea, auras, and taste disturbances after a day. Two questions: 1) How do I communicate this to the Facilities Management ("Looks pretty bright, but it's not flickering. We'll change it for a warmer white"). 2) Do I need to see a doctor about this?
Obviously I've moved out of that office (back to one with some good old (fairly modern) fluorescents with their nice safe 20kHz ballasts), but I'm concerned that the lights will get changed for ones with a warmer colour, but the controllers will remain the same, and the flicker will remain.
It does show up as stripes when you use a webcam – about 6 stripes per frame – so it looks like it's a ~200Hz flicker (~6 stripes × 30 frames/second).
Mainly, I'd like help making a clear and coherent case for the lights to be changed for ones I can live with, and whether that involves seeing my GP. Also, would an optician be able to help.
Obviously I've moved out of that office (back to one with some good old (fairly modern) fluorescents with their nice safe 20kHz ballasts), but I'm concerned that the lights will get changed for ones with a warmer colour, but the controllers will remain the same, and the flicker will remain.
It does show up as stripes when you use a webcam – about 6 stripes per frame – so it looks like it's a ~200Hz flicker (~6 stripes × 30 frames/second).
- Is there would be a more convincing way to make this show: both of my phone cameras showed it for the first second or two, then seemed to get rid of it.
- Is there an easy way to show that this is a proper problem causing me proper symptoms? I'm well aware that people who have problems with lighting environments with fluorescent lights attribute their problems to flicker which hasn't been a problem since the 1970s.
- I'm totally unable to watch 3D movies, as sideways movement ends up turning into a jumbly mess of double images where I can barely detect colour, let alone shape.
- When driving at night, I notice (semi-distractfully) that LED signs on buses tend to jitter around separately from the bus they're attached to
- I see rainbow sparkles in DLP projectors. Well, I actually, I see clear short lived but easily localisable red, green and blue dots.
Mainly, I'd like help making a clear and coherent case for the lights to be changed for ones I can live with, and whether that involves seeing my GP. Also, would an optician be able to help.
In the olden days folks would wear green visors, to cut down on the overhead light, it was big in the newspaper business.
I am not your doctor, but read the stuff about the drug you are taking. Here. It will cause GI problems and neurological problems. I am not sure why you take it, but the side effects are terrible, and likely the cause of your visual disturbance.
posted by Oyéah at 6:10 PM on December 18, 2017 [4 favorites]
I am not your doctor, but read the stuff about the drug you are taking. Here. It will cause GI problems and neurological problems. I am not sure why you take it, but the side effects are terrible, and likely the cause of your visual disturbance.
posted by Oyéah at 6:10 PM on December 18, 2017 [4 favorites]
Best answer: I see flickers in a lot of LED signs too, and can easily see the different frames from an old-school DLP by moving my eyes around. A lot of devices assume 60 Hz (or some subdivision of it) is fast enough, because it's readily available. But it's not.
Get them to put in regular fluorescent bulbs if they can. If not, have the lighting removed entirely and use lights near your desk, with your choice of bulbs.
posted by kindall at 6:15 PM on December 18, 2017
Get them to put in regular fluorescent bulbs if they can. If not, have the lighting removed entirely and use lights near your desk, with your choice of bulbs.
posted by kindall at 6:15 PM on December 18, 2017
When driving at night, I notice (semi-distractfully) that LED signs on buses tend to jitter around separately from the bus they're attached to
I'm sorry I have nothing for you on the main issue, but I can reassure you that this is probably not a neurological issue so much as a perfectly normal consequence of the response speed difference between retinal rod cells (which are sensitive to low light, but slow) and the cone cells that support colour perception.
So this one, at least, is not primarily an electronics-designed-by-bastards issue. You can get the same separation effect around a campfire by facing away from the fire and waving a glowing brand about.
Though it must be noted that the brands don't flicker.
posted by flabdablet at 7:43 PM on December 18, 2017 [3 favorites]
I'm sorry I have nothing for you on the main issue, but I can reassure you that this is probably not a neurological issue so much as a perfectly normal consequence of the response speed difference between retinal rod cells (which are sensitive to low light, but slow) and the cone cells that support colour perception.
So this one, at least, is not primarily an electronics-designed-by-bastards issue. You can get the same separation effect around a campfire by facing away from the fire and waving a glowing brand about.
Though it must be noted that the brands don't flicker.
posted by flabdablet at 7:43 PM on December 18, 2017 [3 favorites]
Best answer: I did have a "funny turn" 18 months ago where I lost the ability to form a coherent sentence for about 3 or 4 minutes
There's no harm in getting a second neurologist's opinion, but this can be a type of migraine aura and since you do get migraines, that's probably what it is. regardless of whether you had a headache afterward or whether it happens often.
How do I communicate this to the Facilities Management
just tell them the problem, bullet points up front, no special approach required: "These lights trigger migraines for me. it's frequent and severe and interferes with my ability to work, so I need to request a different kind of lighting."
the difficulty will be if you have an open floor plan so that everybody has to move, or the entire office has to change the overhead lights, not just your own individual space. but let them figure that out. just make sure you know what kinds of lights are definitely safe and comfortable for you, so they don't worry that they'll have to replace the lights or move more than once.
you talk about "making a case" -- do _not_ go in there with a presentation and proof of the flicker rate or whatever -- that will seem like you're expecting to be disbelieved or argued with. If you never had office-light-triggered migraines until the lights changed, and now you have them reliably, there's your case. Offer to get official medical documentation, if they need it for HR records or something. that + official disability paperwork is the next step if they resist working with you on this, but I wouldn't expect them to require it.
also: if you're not currently taking any preventative migraine medication, look into it? I don't know if it would help in this case but maybe.
posted by queenofbithynia at 7:56 PM on December 18, 2017 [8 favorites]
There's no harm in getting a second neurologist's opinion, but this can be a type of migraine aura and since you do get migraines, that's probably what it is. regardless of whether you had a headache afterward or whether it happens often.
How do I communicate this to the Facilities Management
just tell them the problem, bullet points up front, no special approach required: "These lights trigger migraines for me. it's frequent and severe and interferes with my ability to work, so I need to request a different kind of lighting."
the difficulty will be if you have an open floor plan so that everybody has to move, or the entire office has to change the overhead lights, not just your own individual space. but let them figure that out. just make sure you know what kinds of lights are definitely safe and comfortable for you, so they don't worry that they'll have to replace the lights or move more than once.
you talk about "making a case" -- do _not_ go in there with a presentation and proof of the flicker rate or whatever -- that will seem like you're expecting to be disbelieved or argued with. If you never had office-light-triggered migraines until the lights changed, and now you have them reliably, there's your case. Offer to get official medical documentation, if they need it for HR records or something. that + official disability paperwork is the next step if they resist working with you on this, but I wouldn't expect them to require it.
also: if you're not currently taking any preventative migraine medication, look into it? I don't know if it would help in this case but maybe.
posted by queenofbithynia at 7:56 PM on December 18, 2017 [8 favorites]
3-D movies used to give me migraines as well. But only the kind that had cyclic flickering lenses. Now that non flickering are more prevalent, I'm better.
I just spent the last half you're working in an office again, and overhead lights killed me. Whenever possible I would work with lights off and use the lamp. And about three years ago I worked in an office with no windows thankfully, so we turn off the lights and just used lamps.
Is it an option to turn off the overheads and just use task lighting And some lamps?
posted by tilde at 8:20 PM on December 18, 2017
I just spent the last half you're working in an office again, and overhead lights killed me. Whenever possible I would work with lights off and use the lamp. And about three years ago I worked in an office with no windows thankfully, so we turn off the lights and just used lamps.
Is it an option to turn off the overheads and just use task lighting And some lamps?
posted by tilde at 8:20 PM on December 18, 2017
Best answer: Flicker in fluorescents only went away with the switch to electronic ballasts starting in the late 1990's. Before then the iron ballasts were driven with the 50/60Hz of wall A/C.
Are the lights on a dimmer, or direct LED "tubes" placed into existing Fluorescent fixtures? Or are they completely new luminaries with LED's mounted directly to the frame? The first and second I can imagine a flicker, but the 3rd is usually a constant current DC driver where there should be no flicker at all.
posted by nickggully at 10:03 PM on December 18, 2017
Are the lights on a dimmer, or direct LED "tubes" placed into existing Fluorescent fixtures? Or are they completely new luminaries with LED's mounted directly to the frame? The first and second I can imagine a flicker, but the 3rd is usually a constant current DC driver where there should be no flicker at all.
posted by nickggully at 10:03 PM on December 18, 2017
Many LED lights have compatibility problems with dimmers. This can mean swapping out the dimmer controller to find one that works with the LED panels. Often the manufacturer of the LED panels will recommend a particular dimmer brand and model.
If there is a dimmer involved, one way of demonstrating the problem is to turn the dimmer all the way to maximum and the flicker should go away. Usually, but not always, the flicker will get worse at a lower dimmer setting or just some discrete settings in between. I realize that you say the panels are already quite bright, but if this illustrates the problem, you might have a bit more leverage asking the facilities manager to fix the dimmer.
posted by JackFlash at 10:29 PM on December 18, 2017
If there is a dimmer involved, one way of demonstrating the problem is to turn the dimmer all the way to maximum and the flicker should go away. Usually, but not always, the flicker will get worse at a lower dimmer setting or just some discrete settings in between. I realize that you say the panels are already quite bright, but if this illustrates the problem, you might have a bit more leverage asking the facilities manager to fix the dimmer.
posted by JackFlash at 10:29 PM on December 18, 2017
With regard to your inability to form a coherent sentence, that is called aphasia and is definitely a migraine symptom that I've experienced. You should find a neurologist that will take those symptoms more seriously/ is more knowledgeable about migraines--maybe at a clinic that specializes in migraines? They should be able to support you with whatever medical documentation you need.
posted by _cave at 5:15 AM on December 19, 2017 [1 favorite]
posted by _cave at 5:15 AM on December 19, 2017 [1 favorite]
Best answer: You're working very hard to convince us that your experience is valid. You shouldn't have to. New LED lights have caused you to have eyestrain fairly fast, and nausea, auras, and taste disturbances after a day. The taste disturbances may be migraine - associated. You are an employee and your needs are real, valid, important. You deserve to have this problem resolved. You definitely need to have your primary care doc or a specialist help you with migraines, and maybe en eye doctor will be able to assist with the visual issues with the lights.
posted by theora55 at 6:19 AM on December 19, 2017 [1 favorite]
posted by theora55 at 6:19 AM on December 19, 2017 [1 favorite]
Best answer: Just a related note: LED lighting has been getting worse with respect to flicker recently. The early LED bulbs and lights were all driven by direct current (DC), where the alternating current (AC) from the wall is rectified and filtered/smoothed into a steady voltage. Steady voltage = steady light. In the past year or two, I've been seeing more and more bulbs where the AC from the wall appears to be rectified but not filtered, and the resulting 120Hz waveform is sent directly through the LEDs. This is likely cheaper (less circuitry if you don't filter to DC), and the flicker is above the max perceivable frequency (at least when viewing static objects), but you can still notice an effect. Move something contrasty (bright against a dark background or vice versa) quickly in the light, and you can notice that there isn't a smooth motion blur, but rather a series of images as with a strobe light, but faster.
If anyone wants to avoid this type of bulb, watch out for anything with LED "filaments" (note the example image of flickering, at least in the current page) (image search with more examples). These tend to flicker in this way, at least in my experience. Cheaper lighting in general is more likely to be this style as well, but the "filament" bulbs are the only thing I've found to be a reliable tell, unfortunately.
posted by whatnotever at 10:57 PM on December 19, 2017 [2 favorites]
If anyone wants to avoid this type of bulb, watch out for anything with LED "filaments" (note the example image of flickering, at least in the current page) (image search with more examples). These tend to flicker in this way, at least in my experience. Cheaper lighting in general is more likely to be this style as well, but the "filament" bulbs are the only thing I've found to be a reliable tell, unfortunately.
posted by whatnotever at 10:57 PM on December 19, 2017 [2 favorites]
Response by poster: Thanks for your feedback all.
I followed up with my line manager today, and he's clear that he will fix it and will make sure that the team can work together (we're 6 people out of about 25-30 in the office) somewhere whatever happens. So that's good news, and I'm feeling a lot happier that I can change the situation. Having support to have a reasonable working environment isn't something that I've actually had a lot of experience with.
In terms of the built environment, the complexity comes partly from the fact that it's a big office with a fair number of light fixtures – all of which would have to be altered, either with a new panel, or new controllers – and partly from the fact that e.g. the facilities management people didn't let us label our chairs for the move, and treated the people who asked about it like they were whiny (I didn't ask about it).
And the contractors who do the site maintenance are assigned from a maintenance company who are answerable to facilities management, and there's a whole chain of places where someone can walk into the office, say "I can't see any flicker", and cancel the job, or worse still, make some changes (e.g. replacing the LED panels with warmer white ones) and sign off that job because they can't see the flicker. So being able to measure it would be handy.
Anyway, I think it will get sorted eventually. And if it does, I'll get more confident that I can make reasonable requests and they'll be followed up on. Which I've not really had a lot of in my work life to date.
posted by food of the sock gods at 6:18 PM on December 23, 2017
I followed up with my line manager today, and he's clear that he will fix it and will make sure that the team can work together (we're 6 people out of about 25-30 in the office) somewhere whatever happens. So that's good news, and I'm feeling a lot happier that I can change the situation. Having support to have a reasonable working environment isn't something that I've actually had a lot of experience with.
In terms of the built environment, the complexity comes partly from the fact that it's a big office with a fair number of light fixtures – all of which would have to be altered, either with a new panel, or new controllers – and partly from the fact that e.g. the facilities management people didn't let us label our chairs for the move, and treated the people who asked about it like they were whiny (I didn't ask about it).
And the contractors who do the site maintenance are assigned from a maintenance company who are answerable to facilities management, and there's a whole chain of places where someone can walk into the office, say "I can't see any flicker", and cancel the job, or worse still, make some changes (e.g. replacing the LED panels with warmer white ones) and sign off that job because they can't see the flicker. So being able to measure it would be handy.
Anyway, I think it will get sorted eventually. And if it does, I'll get more confident that I can make reasonable requests and they'll be followed up on. Which I've not really had a lot of in my work life to date.
posted by food of the sock gods at 6:18 PM on December 23, 2017
Response by poster: whatnotever, I think it's not so much that they're just using rectified AC (because, IIRC and IANAElectricalEngineer, but LEDs aren't very good resistive loads, so the current needs to be controlled somehow), but that they transform and rectify the AC to low-voltage DC, and switch it on and off fairly rapidly (Pulse-width modulation (PWM)) so that if the power's on 70% of the time, that means the LEDs are at 70% brightness.
I understand that there are issues with transporting enough power at a low voltage if the switching frequency is too high, so that's why there's an issue.
posted by food of the sock gods at 6:35 PM on December 23, 2017
I understand that there are issues with transporting enough power at a low voltage if the switching frequency is too high, so that's why there's an issue.
posted by food of the sock gods at 6:35 PM on December 23, 2017
I know it's not the main point, but I can't help myself... From the wikipedia link on the filament bulbs: "The large number of LEDs (typically 28 per filament) simplifies the power supply compared to traditional LEDs as the voltage per blue LED is 2.48 < V < 3.7. Some types may additionally use red LEDs (1.63 < V < 2.03). Two filaments with a mix of red and blue is thus close to 110 V, or four close to 220 V to 240 V, compared to the 3 V to 12 V needed for a traditional LED lamp." They really can / do just push wall AC voltage through a bunch of LEDs (possibly with a resistor or something else simple to control current, yes). It's not a given that your panels are designed in this way, of course, but it's certainly a possibility.
posted by whatnotever at 12:40 PM on December 24, 2017
posted by whatnotever at 12:40 PM on December 24, 2017
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As far as making your case, it sounds like they are willing to make changes for you. Can you ask for an old school fluorescent ballast to be installed? (For what it’s worth, when fluorescent bulbs begin to fail, they do flicker. This happens to be a migraine trigger for me.)
posted by PorcineWithMe at 6:10 PM on December 18, 2017 [5 favorites]