Thanks! It’s cool they have done a study on the ‘full-room’ approach.
I think full-room approaches are worth people looking into, but it’s worth noting that they are usually less bright than using SAD lamps (and this goes for the setup described in the pre-print too). As noted, in the pre-print, they put out more light, but because you are usually much further away from the lightbulbs distributed around the room than you would be from a light box on your desk, the mean illuminance at eye level was 1433-1829 lux. By comparison, I have three of the light boxes photographed above on my desk (quite a distance, more than arm’s length), and they’re each around 5000-7680 lux at eye level. Of course, it’s possible to get much larger amounts of light from either approach.
As the pre-print notes, natural summer sunlight exposure has a few characteristics that might be advantageous over typical light therapy, i) much brighter, ii) covers the whole visual field, iii) exposure for many hours of the day, not just a short period in the morning.
I agree that (ii) might be important and potentially a significant advantage of the full room approach over light boxes. IME, one significant difficulty with getting a large amount of light from a small/concentrated source (such as a light box) is that it’s subjectively very uncomfortable. Daylight, conversely, usually provides much more light but without the uncomfortable glare of having a single, very bright light in front of you. Ironically, when I tried setting up large number of bright lightbulbs around my room previously, they are actually less comfortable than light boxes, because without being fully covered by diffusers (as SAD lamps usually are, but which reduces the brightness a lot), the single points of very bright light coming from the bulbs were more unpleasant than the light boxes. Of course, there are very many different ways you could set these up in a room, including having more bulbs, but all with diffusers, so YMMV.
The authors are also right that being able to just sit in a bright room and move around freely within in might be a significant advantage (or a practical necessity) for many people. This isn’t really a factor for me, and I’d imagine many EAs, since I am at my desk most hours and so can be exposed to my SAD lamps pretty easily.
I’m also uncertain about how less bright light spread roughly evenly across the day compares to the typical very bright dose of light first thing in the morning. It seems possible that the brighter light first thing in the morning is superior for circadian rhythm entrainment (and so improving your sleep), though it is also possible that less bright light throughout more of the day is superior (perhaps mediated by higher volume), or that this is superior for SAD, but not for circadian rhythm per se. I’d be interested if anyone knows any high quality studies that tease this apart. I often wonder, for myself, whether it would be better to have a high light dose only relatively early (and then cut it off) or to maintain a high light dose throughout most of the day.
Thanks! It’s cool they have done a study on the ‘full-room’ approach.
I think full-room approaches are worth people looking into, but it’s worth noting that they are usually less bright than using SAD lamps (and this goes for the setup described in the pre-print too). As noted, in the pre-print, they put out more light, but because you are usually much further away from the lightbulbs distributed around the room than you would be from a light box on your desk, the mean illuminance at eye level was 1433-1829 lux. By comparison, I have three of the light boxes photographed above on my desk (quite a distance, more than arm’s length), and they’re each around 5000-7680 lux at eye level. Of course, it’s possible to get much larger amounts of light from either approach.
As the pre-print notes, natural summer sunlight exposure has a few characteristics that might be advantageous over typical light therapy, i) much brighter, ii) covers the whole visual field, iii) exposure for many hours of the day, not just a short period in the morning.
I agree that (ii) might be important and potentially a significant advantage of the full room approach over light boxes. IME, one significant difficulty with getting a large amount of light from a small/concentrated source (such as a light box) is that it’s subjectively very uncomfortable. Daylight, conversely, usually provides much more light but without the uncomfortable glare of having a single, very bright light in front of you. Ironically, when I tried setting up large number of bright lightbulbs around my room previously, they are actually less comfortable than light boxes, because without being fully covered by diffusers (as SAD lamps usually are, but which reduces the brightness a lot), the single points of very bright light coming from the bulbs were more unpleasant than the light boxes. Of course, there are very many different ways you could set these up in a room, including having more bulbs, but all with diffusers, so YMMV.
The authors are also right that being able to just sit in a bright room and move around freely within in might be a significant advantage (or a practical necessity) for many people. This isn’t really a factor for me, and I’d imagine many EAs, since I am at my desk most hours and so can be exposed to my SAD lamps pretty easily.
I’m also uncertain about how less bright light spread roughly evenly across the day compares to the typical very bright dose of light first thing in the morning. It seems possible that the brighter light first thing in the morning is superior for circadian rhythm entrainment (and so improving your sleep), though it is also possible that less bright light throughout more of the day is superior (perhaps mediated by higher volume), or that this is superior for SAD, but not for circadian rhythm per se. I’d be interested if anyone knows any high quality studies that tease this apart. I often wonder, for myself, whether it would be better to have a high light dose only relatively early (and then cut it off) or to maintain a high light dose throughout most of the day.
I find the ReTimer glasses much easier to use, £120 and portable for travelling.