Question

Aren't fluorescent lights bad for our eyes compared to incandescent lights?

Asked by Dannie Loriano
Spokane, WA

The push toward CFL's is suspicious to me because I've read articles by doctors warning that fluorescent lights can tax the eyes because they work by emitting very short bursts of light which cause the eyes to continually attempt to adjust to them. I found the comments logical because when fluorescents start to fail, the light they emit visually vibrates, and causes people to complain. How 'green' can this product be if it can strain our eyes - or is our health not considered in this conversion to CDLs?

Answer

Answered by Doug Garrett

Jarrell, TX

Building Performance & Comfort, Inc.

April 29, 2014

That was somewhat true of the old fluorescent lights, not the new ones. Why you ask? The old fluorescent lights were powered by a magnetic ballast that worked at 60 Hz or 60 cycles per second. That was fast enough we couldn't see the on/off pulses, but for some people they created a problem. When the new fixtures including CFL's were developed we went to electronic ballasts that work at 10,000 Hertz or 10,000 cycles per second. That is so fast that there is no way it is detectable to the eye or brain. That's why you don't see any discussion of this issue today.

Tagged In: Green lighting

Do you have a question about greening your home? GreenHomeGuide invites you to Ask A Pro. Let our network of experienced green building professionals – architects, designers, contractors, electricians, energy experts, landscapers, tile & stone specialists, and more – help you find the right solution.