Light Box Selection

Criteria for Light Box Selection

Any light box you buy should have been tested successfully in peer-reviewed clinical trials, or have been calibrated by an independent lab to demonstrate equivalent output level, diffusion, spectrum, UV filtering, and field of illumination.

For many years, the Center for Environmental Therapeutics provided a list of companies - most of them established in the early years of light therapy - that sell light boxes and related treatment apparatus. This has grown into something of a cottage industry, with many recent competitors selling clinically untested apparatus, and several of the original companies introducing new models with unjustified claims for efficacy and ocular safety. There is a whole new set of concerns now, and without federal or professional regulation of standards, the medical and scientific basis of the field is placed at risk by inadequate products and advertising.

CET's Board of Directors, therefore, has decided to discontinue the suppliers list, but continue to emphasize standards for light box design that consumers, doctors and insurance companies should keep in mind when selecting apparatus for purchase. Additionally, CET has identified a specific set of devices that have been carefully evaluated in clinical trials, and made them available at our On-Line Store, with earnings that support this website.

Our Selection Criteria


After close consideration of thee major factors - clinical efficacy, ocular and dermatolgic safety, and visual comfort - we recommend the following criteria for light box selection:


  • Any light box you buy should have been tested successfully in peer-reviewed clinical trials.

  • The box should provide 10,000 lux of illumination at a comfortable sitting distance. Product specifications are often missing or unverified.

  • luorescent lamps should have a smooth diffusing screen that filters out ultraviolet (UV) rays. UV rays are harmful to the eyes and skin.

  • The lamps should give off white light rather than colored light. "Full spectrum" lamps and blue (or bluish) lamps provide no known therapeutic advantage.

  • The light should be projected downward toward the eyes at an angle to minimize aversive visual glare.

  • Smaller is not better: When using a compact light box, even small head movements will take the eyes out of the therapeutic range of the light.