Full-spectrum compact fluorescent bulbs improve color perception and productivity. Fluorescent bulbs fit the same socket as regular light bulbs and are cheaper in the long run.
Fluorescent lamps work differently from regular incandescent lamps. They have ballast to stabilize the flow of current through the bulb, and a tube filled with mercury vapor in inert gas. The inner side of the tube is covered with white fluorescent material (phosphor). They are 3-5 times more energy-efficient than incandescent lamps and last 10-20 times longer. Fluorescent daylight tubes are used in stores and offices. The humming and buzz of the ballast, as well as "harsh" feel of the light, are eliminated in more expensive full-spectrum lamps with electronic ballast. Compact fluorescent lamps (CFL) are same gas-filled tubes coiled or bend to fit regular socket. They are slightly less efficient then regular tubes, but more practical if you are switching from regular lamps without major surgery. I replaced all incandescent lamps at home with compact fluorescent bulbs four years ago, and they are still working. My reasons were not eco-friendliness and energy conservation. I cannot function in dim light. A 100-Watt incandescent bulb in a desk lamp is too hot next to my face, and its light is too yellow and ruins color perception.
Pros: Compact fluorescent bulbs last 10,000 hours. That is 10-15 times longer than incandescent lamps (750 hours). Note that switching on/off exhausts CFL's resource faster than regular bulb's. They are approximately four times more energy-efficient: a full-spectrum 23-Watt Spiralux Vita-Lite lamp emits 1400 lumens -- as much as a 90--100-Watt incandescent lamp. Daylight fluorescent bulbs produce light close to the real outside light (not the direct sunlight). That means it lets you tell deep blue from deep purple on a photograph of a fabric sample, allows color painting and keeps you awake and productive in dark hours or overcast days, as warmer, redder incandescent lamp light does not. Cheap two-phosphor lamps produce harsh, cold light no one likes. A four-phosphor lamp, like Spiralux Vita-Lite above, can subjectively appear "cold" only with insufficient lighting: human eye expects "cold", blue outside light to be bright, and dim light to be warmer. Like warm fading light of sunset, perhaps. I keep light at home normally very bright -- 5--7 23-Watt Spiralux Vita-Lite fluorescent bulbs in small home office. Note that "keeps awake" is not subjective: light/dark input regulates one's circadian rhythm, and bright light is a well-known stimulator. I need a half-hour to hour wind-down with dim, soft light to sleep normally.
Cons: Some people find outside light inside uncomfortable, unwelcoming, not cozy. I heard it from several people, but I don't get it, personally. CFL takes up to thirty seconds to light up, while incandescent lamp lights perceivably immediately. Fluorescent lamps don't die at once: they start humming or buzzing if ballast fails first, or they start flickering, or part of phosphor fails (burns out), producing dark spots or altered spectrum. They are more expensive initially: cheapest ones come at $5 a piece, good ones at $15-$27 per compact lamp meant to replace a regular one. They have an odd shape. I don't see any problem here, but some people do. The only problem I personally faced with fluorescent lamps is mercury inside. When my toddler son tripped on a cord and sent down a floor lamp with five fluorescent lamps, two of them broke in fine glass splinters and dust, releasing approximately a year's elemental mercury exposure dose. Poison Control Center's advice was very common sense: open the doors and windows and go for a walk for an hour, than vacuum the glass. Nobody in my family had any evident poisoning, but mercury accumulates, and every exposure counts. Fluorescent bulb disposal is non-trivial. The best way is to bring them back to the store, or take them to a disposal/recycling facility. Fluorescent bulbs are not dimmable.