Visual overstimulation

[Jumpinbare]

Many cheap LED lights use only halfwave rectification, causing them to flicker at the frequency of the AC lines (50 or 60 Hz, depending on country). Also, dimmable LED devices tend to use Pulse Width Modulation, which can also appear to flicker, depending on the PWM base frequency.

 

[Roisin]

My most worrying visual overstimulation while driving is the effect of rain combined with window wipers and oncoming (increasingly brighter) headlights in the dark, it uses up a lot of my reserves.

For most of my 20s and 30s I was doing regular long distance drives in the dark. I believe the impact of visual overstimulation underpinned by the stress I was feeling at this stage led to shutdowns. Pre diagnosis I pushed through and had a meltdown at some point later, post diagnosis I recognised I had to pull over a few times to just allow the shutdown to happen.

For the effect of oncoming lights I use anti-glare glasses and they help reduce the sharp pain my more sensitive left eye experiences.

My 5 year goal is to work from home, and slowly Im coming to accept that I'll need to live in an urban area with public transport as a long term solution.

 

[thejuice]

There is a lot of conversation around sounds being overstimulating. After usijg earplugs, headphones etc. for some time, I have noticed that visual stimuli exhaust me as well. I have noticed that seeing a crowd (shopping), traffic or television can be very tiring for me. Movement. What kind of visual stimuli are tiring for you? Kinds of lighting? The kind of lighting they often use in shops is tiring too, because it blinks.

Ive heard about 10% are PMW (Pulse Wave Modulation) sensitive, to flickering lights. I think I might be too. Do you actually see it blink or is it just a sensation you feel?

 

[thejuice]

When servicing computers for people many years ago I had a couple of clients that had this problem, this was back in the days of the old CRT monitors. A 60 hz refresh rate was too slow for them, they could see the flickering and it was annoying and distracting for them and one bloke said if he looked at the screen for too long he got motion sickness from it. These people needed a minimum refresh rate of 75 hz.

That said, I've got friends that have cheap LED replacements for flouros and there is no "refreshing" on them, they are just "on". If LED lights are flickering then they're broken.

[Edit] An interesting little trick you can play on yourself with refresh rates - hold a vibrating device such as an electric toothbrush or electric shaver against your skull next to one of your eyes, then look at your TV, the clock on your microwave, etc.

I use to play computer games on 30hz because im in PAL region, with terrible frame rates and didnt have issues. Seems to be something that has gotten more acute with age, like car sickness too. I will try the toothbrush skull trick!

Many cheap LED lights use only halfwave rectification, causing them to flicker at the frequency of the AC lines (50 or 60 Hz, depending on country). Also, dimmable LED devices tend to use Pulse Width Modulation, which can also appear to flicker, depending on the PWM base frequency.

I used to have Philips LED dimmable light bulbs. I wasnt that impressed as blutooth was unreliable and i reckon it must have had PWM issues like you said. I might try a high end, low lumen LED bulb then, if such a thing is available.

 

[vergil96]

Do you actually see it blink or is it just a sensation you feel?

Both depending on the lighting