[chris (OP)]

I was asked this question recently by researchers at BBC Radio 4's iPM programme. Indeed their blog has received a number of entries from people concerned that the UK government want to ban incandescent bulbs in favour of the energy-sparing equivalent. The migrainees argue that this will make life hell for them.

I am wondering if anyone has any personal experience of this, either as a sufferer or someone affected by the phenomenon, or as a doctor / neurologist who has been treating or investigating cases.

Chris

[techmind]

Even though they typically use "high frequency" (20 to 50 kiloHertz) driving, compact fluorescents can still flicker (100Hertz modulation in light output) because they still run off 50Hz mains and their smoothing capacitors are undersized (for reasons of cost and compactness). I imagine this could have physiological effects in sensitive subjects.

They also emit a certain amount of UV. I used to think this was overhyped, but I now observe this can often be enough to make fabrics, paper, dust etc. start to fluoresce. This fluorescence will tend to lower the contrast of text on a printed page, making it harder to read. I guess that for people whose reading is already marginal (perhaps due to nothing more than a fairly low light-level), this could cause eyestrain and physiological symptoms...?

Finally, the spikey emission spectrum of fluorescent lamps (and coupled with object-fluoresence, above) does distort the colours in the room. Personally I find this annoying (but am not a migraine-sufferer)... I suppose if some people's brains were wired to perceive colour more literally than average, this might cause them more fatigue too?

[chris (OP)]

Thanks Techmind

A point I made was that most of the shades and fittings currently present in the average home have been selected and developed to optimise light transmission or softening of wavelengths from incandescent bulbs.

Hence, plugging fluorescents into these shades or fittings might result in a very different illumination experience in the room concerned; consequently, although you may have replaced the incadescent with a "60W equivalent" bulb, the amount of light in the room may be more or less than expected, and may involve other wavelengths you weren't prepared for.

The result can be an unsettling illumination experience, which I suspect many people, myself included, find stressful. Since stress is implicated in 80% of migraines, I'd say this is one way that these bulbs might cause the condition.

What does everyone else think?

Chris