A reader asks:

 I use my light box for about 30 minutes each morning. However, I’ve been thinking about ways to brighten up my rooms all day. I find that I’m much more cheery if the room where I’m working is bathed in bright, warm light. Given that I shouldn’t leave my 10,000 lux light on all day and given that you recommend against full-spectrum lighting, what might be my best options for bathing my rooms with light?


The lux level received from a light box strictly depends on your distance from the source. There would be no problem leaving your light box switched on during the day if you are not physically close to it. By remaining outside the active therapeutic range (for example, more than 3 feet using the Daylight 10,000 lux Clinical Model we recommend) you can continue to enjoy the enhanced ambient room illumination. For brightening other rooms without the light box, we recommend diffuse or indirect illumination from standard incandescent (including halogen) lamps or fluorescent lamps rated 3000-4000 Kelvin color temperature. In general, the lower the color temperature, the “warmer” (less blue, more pinkish) the hue. As you suggest, for long-term comfort it makes sense to avoid specialized fluorescent or incandescent lamps with higher color temperature, which exacerbates glare.