sentences:  The long life of LEDs, expected to be about 50 times that of the most common incandescent lamps and significantly longer than fluorescent types, is advantageous for users but will affect manufacturers as it reduces the market for replacements in the distant future.The human circadian rhythm can be affected by light sources.The effective color temperature of daylight is ~5,700K (bluish white) while tungsten lamps are ~2,700K (yellow).