Fluorescent bulbs don’t burn out all at once like incandescents do. Instead, they lose their apparent wattage output over time. In my experience, CFLs have a half-life of about 30 months in normal usage. In other words, a 1000-lumen CFL will produce only 500 lumens after two-and-a-half years. By the time the rotten thing finally does completely give up the ghost, you’ll be half-blind from squinting. Read on at: http://pjmedia.com/lifestyle/2012/07/23/the-sad-truth-about-bad-bulbs/?single... Seriously folks... switch to LED