Since the start of CET in 1994, our goal was to highlight significant benefits of bedroom dawn simulation, as introduced by the Columbia University chronotherapy group in 1989, following years of research and clinical trials.
The first versions of a dawn simulation system for consumers closely resembled the naturalistic twilight transitions of the outdoors, with gradual, smooth dawn transitions from starlight to sunrise. It was largely based on the laboratory model (see photos), and it worked successfully in hundreds of bedrooms. However, the device and its placement over the bed was cumbersome, and lamp + control box were expensive.
Lighting companies quickly introduced less complex and less expensive models to the market, however they were untested in adequate clinical trials. Just as with miniature light boxes, the manufacturers made ― and still make ― unwarranted claims of efficacy.
When the limited stock of the initial naturalistic dawn-dusk simulator ran out, we selected the simplest ― and one of the least expensive ― commercial alternatives, called the Per2. This model was unique among other “dawn alarm clocks”, which featured gimmicks like sounds and scents that override the circadian rhythm wake-up signal. When the limited stock of the Per2 ran out in late 2021, the company decided to discontinue production.
Unfortunately, that currently leaves CET without a dawn (or dawn + dusk) simulator to recommend to our visitors. We urge people to take advantage of the well-established alternative, bright light therapy, until a sufficient twilight system is available to the public. CET is actively collaborating with Zeitgeber Lighting GmbH, an Austrian partner, on a novel dawn–dusk simulation system currently in the prototyping and early validation phase, with initial prototypes expected in 2026. We look forward to sharing updates and making the system available to the CET community once it has been rigorously tested and is ready for broader release.
If you would like to be notified as progress continues, or are interested in providing confidential feedback as we continue to refine the system and/or participate in early user testing, we would also welcome hearing from you. Please contact info@cet.org.
