Can flashing lights cause epileptic fits?

[Racing roadkill]

The biggest problem with flashing front lights are on cycle paths, little or no street lighting, the blindingly high intensity flashing coming at you head on. At times I've been totally unable to see where I'm going and have had to stop, always doing so at an angle so as to block the progress of the culprit.

The last time someone tried that trick on me, they lost the ensuing game of 'chicken'.

 

[ufkacbln]

The last time someone tried that trick on me, they lost the ensuing game of 'chicken'.

With risks like that ...can I recommend that you wear a helmet as your risk is far higher than that of the average cyclist

 

[theclaud]

With risky like that ...can I recommend that you wear a helmet as your risk is far higher than that of the average cyclist

 

[ufkacbln]

If you've suffered a fit in the last 12 months, then no.

The blanket 12 month ban is unfortunately a self perpetuating myth

There are a whole range of restrictions and differing periods. Can be as little as 6 months or no restrictions at all:

Isolated seizure:

If you have a seizure after being seizure free for at least five years, the driving agency may consider this to be an isolated seizure.

This can only apply on one occasion.

If you have had an isolated seizure you may be allowed to drive when:

• you have been seizure free for at least six months and
• your consultant thinks it is unlikely you will have another seizure and
• the driving agency is satisfied that as a driver you are not likely to be a source of danger to the public.

You can also hold a licence whilst experiencing fits if your seizures are "Asleep only", or in some other defined cases

• They have only had seizures while they sleep
• They have only had seizures that do not affect their consciousness
• Their doctor changed their dosage or medication, but they have now gone back to the original dosage or medication.

You may also have to stop for a period of time if your medication changes and the medical advice is that there may be a fit during the interim period


For a detailed look try Epilepsy Action who have a lot of informed and accurate information on these subjects

 

[the_mikey]

Many modern lighting systems flash to some degree, an LED flashing at 30Hz will look like a constant light until it's moving past you and some speed, the reason for this is it's easier and more efficient to turn an LED on and off with different mark-space ratios to control the apparent brightness than it is to control the current to the LED as this generates more heat than the typical pcb mounted resistor can handle before burning out.

It's particularly noticeable on cars with LED lighting systems.

 

[ufkacbln]

Many modern lighting systems flash to some degree, an LED flashing at 30Hz will look like a constant light until it's moving past you and some speed, the reason for this is it's easier and more efficient to turn an LED on and off with different mark-space ratios to control the apparent brightness than it is to control the current to the LED as this generates more heat than the typical pcb mounted resistor can handle before burning out.

In fact for the older ones amongst us, this was the reason that LEDs were not allowed

When the first "Vistalite" LED rear lights came out they were not acceptable because the LED was by definition flashing and therefore not compliant

 

[brand]

If you've suffered a fit in the last 12 months, then no.

You must have two episodes before your classed as epileptic. If you have one you are not allowed to drive for 3 months. I am not sure if you have a one barred from driving as they have done some changes since I was barred 20 odd years ago.
To answer the OP my last reading was about 5% of eppys are effected by flickering lights. The flashing must be between 2 figures so many per minute. You would assume that the makers would take that into account. I would be surprised if they all do.
Computer don't flash television do but you had to be close enough to see it. They have now doubled the flicker rate so you cannot see it.

 

[ColinJ]

Are you permitted to drive if you suffer from epilepsy?

A stall holder on our local market suffered fits as a young man but medication stopped them so he had been driving ever since ....

If you've suffered a fit in the last 12 months, then no.

The stall holder didn't turn up for a few weeks, and when he did he had a new assistant. The fits had suddenly returned as he had been driving back down the M62 in his van. The result was a multiple pile-up, fortunately not causing serious injuries or deaths! His licence has been taken away from him so his assistant is now the driver. He told me that whether he gets his licence back depends on whether his new medication turns out to be 100% effective in the long term.

 

[brand]

Computer screens do flash, usually at 60Hz.

Some disagreement on the net about this. Basically you have to be able to see the flash/flicker for it to have an effect.
https://www.epilepsy.org.uk/info/photosensitive-epilepsy/computer-television-screens

 

[Kookas]

Some disagreement on the net about this. Basically you have to be able to see the flash/flicker for it to have an effect.
https://www.epilepsy.org.uk/info/photosensitive-epilepsy/computer-television-screens

Sorry, I Googled it and yeah, you're right, LCD pixels don't normally switch off between frames. Indeed, in this slow-mo video you can hardly see the change at all because the refresh overlaps the previous one.

View: http://youtu.be/DjMROqGSaOE

That said, I believe the same applies for LCD/LED TVs.

View: http://youtu.be/BBgFampjkPs

 

[classic33]

Whats the flicker/flash speed of fluorescent lighting, especially the newer compact type bulbs.
Warned about the possibility of these triggering a fit.
You can't actually see it flash/flicker, but some do come with the warning about photosensitive epilepsy.

 

[Flick of the Elbow]

The last time someone tried that trick on me, they lost the ensuing game of 'chicken'.

Sadly, such a selfish and aggressive attitude is typical of many who use flashing lights, they don't care about their effect on anyone else. They are the cycling equivalent of 4x4 drivers.

 

[the_mikey]

Whats the flicker/flash speed of fluorescent lighting, especially the newer compact type bulbs.
Warned about the possibility of these triggering a fit.
You can't actually see it flash/flicker, but some do come with the warning about photosensitive epilepsy.

I suspect at least 50Hz , but the phosphor coating has some persistence which masks any apparent flash or flicker.