TempoLife › Features › The dark season: light, sleep and vitamin D › lamps
Choosing a light box, wake-up light or daylight lamp
The three lamp categories, what each one is actually for, and the numbers that separate them.
This is seasonal self-care information, not a diagnosis and not treatment advice. Seasonal affective disorder is a clinical diagnosis made by a clinician; bright-light therapy is not safe to self-start for everyone (bipolar disorder and some eye conditions come first); and any measured vitamin D deficiency is treated at a clinician's dose, not a supplement-shelf one. If thoughts of self-harm are present, the step is crisis services now — the <a href="/therapists">mental health page</a> carries the national crisis lines.
The three categories
A therapy light box is the treatment device: 10 000 lux at a stated distance, UV-free, used 30 minutes in the morning for the seasonal pattern. A wake-up light is an alarm clock that brightens gradually before the set time; it makes waking gentler and some people report better winter mornings, but its peak output is hundreds of lux, not the therapy dose, and no trial used one. A daylight lamp is furniture: a high-colour-temperature lamp that makes a room feel like midday without producing circadian doses at any usable distance.
The numbers that matter on a box
Lux at a stated distance — and the distance is half the spec, because 10 000 lux at 20 cm means your nose against the plastic. UV-free, explicitly stated. A screen size that lets the light reach the eye from a normal sitting position without aim. And an honest price: the electronics are LEDs in a plastic housing, and no lamp has a therapy claim worth paying a medical premium for.
Colour temperature and the evening problem
Daylight-coloured lamps (5 000 K and up) read as "bright" to the eye but deliver the same few hundred lux indoors as warm ones — colour temperature is not intensity. The evening rule is the reverse of the morning one: after sunset, dim and warm is the setting, because the same blue-rich light that helps at 8 am pushes the clock later at 8 pm. Screens follow the same physics: night mode in the evening, not brightness in the morning.
What a lamp cannot do
No lamp makes vitamin D — that needs UVB, which therapy boxes are designed not to emit, and tanning lamps emit far more UV than the eye or skin should take for the purpose. No lamp replaces daylight for the clock as well as going outside. And no lamp treats depression by itself; where mood is the concern, the lamp is a tool inside a plan, not the plan.
Light therapy dosing: the bright-light trials (10 000 lux, 30 minutes, morning). Vitamin D: the Nordic national nutrition recommendations. Circadian facts: the standard chronobiology literature (melanopic response, dim-light melatonin onset). The depression line: clinical diagnostic practice — seasonal affective disorder is diagnosed by a clinician. Checked 2026-09-06.
Frequently asked questions
Is a more expensive light box better?
Not in any way that matters. The active specification is 10 000 lux at a usable distance and UV-free, and that is commodity electronics. Pay for the right numbers and a screen size you can live with, not for a brand story.
Can I use a tanning lamp for winter mood?
No. Tanning lamps are UV sources and a skin-cancer risk, and the UV they deliver is not the treatment for the seasonal pattern — the trials used visible light at 10 000 lux. A therapy box is UV-free by design; a tanning lamp is the opposite of that.
The rest of the dark season
The dark season
All six winter pages, with the numbers behind them.
Light therapy: the dose that works
10 000 lux for 30 minutes in the morning — the dose the trials actually used, and how to deliver it.
Vitamin D in the dark season
What latitude does to skin synthesis, and what the Nordic recommendations actually say about supplements.
Winter sleep: longer, later and how to steer it
The dark season pulls sleep later and longer; the lever that fixes it is morning light, not evening discipline.
Winter blues and when it is depression
The difference between the seasonal dip and seasonal affective disorder, and the line where help is needed.
Track the season, not just the symptoms
TempoLife keeps sleep, steps and daylight in one picture, so the difference between your November and your June is on the chart instead of in your memory.