Yes, 10,000 lux for 30 minutes is still the standard for SAD

10,000 lux for 30 minutes, first thing in the morning, is still the gold standard for late-winter SAD. The research hasn’t really budged on this in decades.

A few things to keep straight: the 10,000 lux number refers to the intensity at the device’s surface (usually measured at about 12–18 inches). That’s not the same as the ambient light in your room — it’s assuming your face is close enough to the lamp. Most reputable clinical trials used these boxes, and 30 minutes is the sweet spot where most people respond without feeling overstimulated or cranky.

If you’re using a weaker lamp (say 2,500 lux), you’d need to sit there for two hours. Nobody does that. So 10,000 lux for 30 minutes is the pragmatic winner. Some newer studies have poked at shorter durations (15–20 minutes) or higher intensities (like 15,000 lux), but the evidence isn’t strong enough to change the recommendation. The standard works for enough people.

Also, timing matters more than most realize. Morning light exposure (ideally within 30–60 minutes of waking) shifts your circadian rhythm and directly counters the winter lethargy. Late afternoon sessions can actually make sleep worse for some people.

Don’t overthink the lux meter. If the box says 10,000 lux and it’s from a reputable manufacturer, sit 12–18 inches away for 30 minutes, do it early, and give it two weeks. If that doesn’t work, then start fiddling with duration or timing.

Future you will appreciate not having to measure lamp output with a phone app.