Light and Health
Daily bright light exposure is essential for wellbeing
For a much more in-depth look at light and human health, read founder Nat Martin’s piece on using light to affect your health here⇗. We’ll link to sections of it throughout this page.
SAD (Seasonal Affective Disorder) describes a form of depression that typically occurs during the winter months. Although SAD is a widely used term, the condition’s underlying causes are poorly understood. What is clear, though, is that bright light therapy has consistently been demonstrated as an effective treatment for the disorder⇗.
Bright light therapy has also been shown to enhance wellbeing for people not suffering from SAD. Regular exposure to bright light, particularly early in the morning, plays a crucial role in keeping your circadian rhythm in sync with your actual schedule ⇗. Through this mechanism, regular daily bright light exposure can lead to improvements in cognitive performance and metabolic health.
Bright light exposure has also been shown to have short-term and immediate effects on improving alertness and cognition ⇗. There is also new evidence that exposure to light can keep your eyes healthy for longer, preventing the development of short-sightedness ⇗.
The consensus from bright light therapy research suggests around 5,000 lux-hours of exposure is required to achieve optimal benefits ⇗. This could be achieved, for example, by exposure to 10,000 lux for 30 minutes or 5,000 lux for one hour.
The bright light therapy status quo
Most SAD lights on the market are simply not that bright. This means that you need to sit very close to them, typically 5-30 cm (closer than you’d hold a book), or look at them for several hours to reach 5,000 lux hours. In practice, this means light therapy often feels like a chore, with evidence showing that adherence to bright light therapy regimens can be a significant challenge ⇗.
| Light | Lumens |
|---|---|
| Phillips ES R63 3W | 210 |
| Lumie Task Lamp | 1300 |
| Beurer TL130 SAD Light | 440 |
| Sunday | 34000 |
Sunday is 30–50 times brighter than the market-leading SAD lights, with a 34,500 lumen output and 10,000 lux at 60 cm from the sky panel. This far greater output means that you can experience physiologically significant levels of light over a much larger area, transforming light therapy from a chore to a seamless experience in the background of your life. For example, with Sunday hung over a typical 120cm dining table, four people seated all receive over 5,000 lux - everyone at the table for an hour over lunch would have achieved a recommended light intake.
A sunlight and sky machine
The sun and the sky together illuminate the world outdoors. All the natural light we see originates from the sun but the atmosphere scatters that light, and reflects it down as the bright, diffuse blue sky.
Sunday’s optics have been designed to replicate this, with the large panel scattering light the same way that the atmosphere does. Conventional overhead lighting originates from a single point; at higher intensities, most people find this overwhelming and unpleasant. With Sunday’s light cast from a large, bright blue surface, the overall effect is that of being outside on a clear day: vivid, pleasant brightness.
The right light at the right time
Sunday has variable colour temperature and continuous dimming, so the light it casts is always appropriate for the time of day. Its colour temperature can be set from a cool 6000K, ideal for the morning, to a warm 2650K firelight, pleasant and welcoming after sunset.
Having the right colour temperature and brightness for the time of day is essential for our health as well as our comfort. Generally, brighter and bluer light is better early in the day, and warm, dim light is better in the evening ⇗. Learn more about choosing the right colour temperature and brightness for the time of day here ⇗. With adjustments to colour temperature and brightness scheduled automatically, you always have the light your body needs.
We evolved to live outside, in daylight.
There is growing evidence that daily sunlight exposure is essential for health and wellbeing. We evolved to spend our days outside. If you can’t go outside - and many of us can’t as much as we’d like, we’re working, caring, travelling, training, and a million other things - light from Sunday is the closest thing to daylight you can get.