A reader asks:

 In all of the books I have read regarding SAD, they show a dawn simulator that looks like a set of track lights. I have been looking for this type of dawn simulator for the last ten years and have never found one. Is this type actually available?

Answer:

There are three separate functional components of a dawn simulation system:

  1. The electronics that control the timing and intensity of the light.
  2. The lighting fixture.
  3. The diffusing lens covering the bulbs.

There is nothing special about a track-lighting design — it is an arbitrary selection of apparatus driven by the electronic controller unit. It is very possibly a bad choice, since the light aimed at the subject may not be diffused, and may also be highly directional (in which case even slight changes in sleeping posture might greatly reduce the light exposure). A configuration we have recently applied with success uses a commercially available standing lamp with an articulating arm for positioning a diffused light for optimum illumination of the pillow area. In addition, the unit provides upward illumination toward the ceiling, so the whole room brightens as the dawn progresses. For detailed info, see the CET store.