Bright light therapy has been studied extensively since the early 1980s and has clinically-proven effects on mood, energy, focus & sleep. Though the bulb in the HappyLight© Therapy Lamp looks like a regular bulb, HappyLight© therapy lamps are uniquely designed with a special ballast to ensure a lux measurement (or light intensity) far greater than an ordinary lamp. It is the amount of lux - and brightness of the lamp - that makes the HappyLight© effective. If you are new to light therapy and the science behind it, we highly recommend Dr. Norman Rosenthal's book Winter Blues if you'd like to learn more.