Is Fluorescent Light Flicker at Work Causing Your Headaches?

Have you ever wondered why your eyes and head sometimes hurt after sitting in your office for awhile? Look up at the lights for a possible answer. You may not notice anything other than a fluorescent fixture. But what's happening inside the fluorescent tubes is fluctuating light output.

Input power frequency variations inherent in the relationship between the magnetic ballast and the lamps cause the fluctuations. The pulse is too rapid for most people to see. However, some people sense the pulse and have a physical reaction. The same flicker, also known as striation, may occur with screw base CFLs that have an integrated magnetic ballast.

Normally, the flicker problem is greatest with T12 fluorescent lamps and magnetic ballasts. People report far few flicker issues with T8 fluorescent lamps and electronic ballasts. The best solution both for the flicker and for increased energy savings is to retrofit your light fixtures to T8 lamps with high efficiency electronic ballasts. Likewise, CFLs with integrated electronic ballasts will have reduced flicker.

These days, there are a large number of options for retrofitting T8 fluorescent fixtures to LED. Manufacturers have tried to give electrical installers a range of options for how to switch over to LED. LED tubes are more energy efficient than fluorescent, and have a longer rated life.

Beyond just the fluorescent tube, the magnetic ballast itself may be causing you problems. Magnetic ballasts can give off an audible buzzing noise that is extremely noticeable to everyone, or just subtle enough to affect those sensitive to it.

By contrast, incandescent and halogen bulbs do not cause flicker. A heated filament (usually tungsten) produces light. No ballast is involved. It's simply electricity into the filament and the bulb is illuminated.

Similarly light emitting diodes or LEDs produce extremely stable light output. LEDs are semiconductors. When electrons move through the semiconductor, out comes light, without flicker. However, LED lamps still require a driver, either external like a fluorescent ballast or integrated into the light source.

If you are extremely sensitive to flicker, avoid fluorescent lights. You should have no problem with incandescent, halogen or LED light sources. And if you work in an office, school, or warehouse with extremely old fluorescent fixtures, simply updating to T8 tubes and electronic ballasts may provide relief.