At first I was a little suspicious of Citizen's "Eco drive" light-powered watches, because I have been disappointed with earlier "solar-powered" watches: failure to stay charged in normal use, and, after too short a time, just plain failure to operate at all. And their appearance was compromised by ugly little black solar chips right on the watch face. Citizen has merged several new technologies (amorphous silicon photocells, low low low power semiconductor chips, and long-life lithium titanate batteries) to produce a watch that you just put on your wrist and wear - forever. The battery rarely or never needs to be replaced! If you take the watch off and put it away (to wear some other watch, say, like your wonderful but technologically obsolete Rolex), it will run for months in the dark and will still be keeping good time when you put it back on. In other words, a watch with no worries. The solar cell is UNDER the watch face, so it doesn't show, so the watch can be as good-looking as any other. I have not had a chance to confirm the time-keeping accuracy of the watch, or Citizen's longevity claims, but based on the technologies Citizen is using I expect no problems. Citizen has been gradually refining its Eco drive technologies for more than 15 years. I have bought a couple of these watches and I'm very happy with them.