Yes. A light that brightens the whole room can give you the same kind of dose as a SAD box, because what counts is how much light reaches your eyes and for how long, not which device it comes from. In a 2022 randomised trial, people with SAD who spent their days in a very brightly lit room improved by about as much as people using a 10,000 lux box. Sunday Light, the artificial skylight we make, gives 10,000 lux at 60 cm and lights the room from the ceiling.
How the SAD light dose works
The standard dose is 10,000 lux at the eyes for 20-30 minutes, within the first hour after waking, with the box about 16-24 inches from your face (Mayo Clinic). Brightness and time trade off: in earlier trials, 2,500 lux for about two hours gave comparable results. Our guide to light therapy for SAD goes through the trials.
Distance is what makes boxes a chore. The light falls off steeply as you move back: Lumie's Vitamin L gives 10,000 lux at 20 cm, 5,000 at 30 cm and 2,500 at 50 cm. Bigger boxes buy you room. The Carex Day-Light Classic Plus ($169.99) reaches 10,000 lux at 12-14 inches, and the Alaska Northern Lights NorthStar 10,000 ($354 in October 2026) at 24 inches. Yale's winter depression programme lists the NorthStar among the full-size units it recommends. With any of them, you sit facing the box for the session.
What a whole-room trial found
The trial (Sandkühler et al., Depression and Anxiety, 2022) gave 62 people with SAD four weeks of either a very brightly lit room at home for at least six hours a day, or 30 minutes a day at a standard 10,000 lux box. The rooms averaged about 1,400-1,800 lux at eye level, well under the box's figure, and both groups improved by similar amounts.
Within the bright-room group, more light went with more improvement. Each doubling of lux at the eye predicted about four more points of improvement on the SAD symptom scale, and the people above 1,400 lux improved by more on average than the light-box group. The authors concluded that whole-room light seemed about as effective as the standard treatment without tying anyone to a box, and that brighter rooms would likely work better.
What Sunday Light gives a room
Sunday puts out 34,500 lumens, about 30 times a typical SAD lamp, from a sheet 120 cm across that hangs from the ceiling. Sitting under it you get 5,000 lux and more, reaching 10,000 lux at 60 cm from the sheet, and because the source is large and overhead, the light reaches you across the table under it rather than only in one seat facing a box. You eat breakfast or work under it, and the light comes with the room.
Mornings are when bright light does most for SAD, and Sunday starts the day at cool 6000K, then goes warmer and dimmer through the afternoon. We recommend having it off by around 6pm. It emits visible light only, with no UV, and it is flicker-free. Professor Russell Foster, Director of the Sleep and Circadian Neuroscience Institute at the University of Oxford, advises us: "It produces a level and quality of light that approximates sunlight, yet its design allows prolonged use that is both comfortable and convenient. Critically, you do not have to sit next to the device to get the levels of light that will deliver physiological benefits."
If you will sit at a box every morning, it is the cheaper route and well supported by trials. If you know you won't, Sunday Light vs SAD lamps sets out the differences in full. Sunday Light, our sunlight fixture, is £5,900 in the UK, $6,900 in the US and €6,900 in Europe, with free worldwide delivery. Any qualified electrician fits it in 1-2 hours, and it needs a ceiling of 240 cm or more. The full specification is on the indoor sunlight ceiling light page. How to light a north-facing room covers colour temperature through a UK winter, and bright light for afternoon focus covers what bright light does for alertness in the afternoon.
