A Lumen is a measure of the total amount of visible light to the human eye from a lamp or light source

For instance, if you look into a 100 watt lightbulb you are being subjected to about 1600 lumens. That feels very bright because the light is close by.

But all light isn’t equal.

If you look in a general easterly direction on a cloudy day in winter, you will be experiencing far more lumens than even the brightest indoor lights can provide.

Which is partly why outdoor light (or even the light coming through a window) is far better for our mental health and for resetting the circadian rhythms that help us get better sleep, than our artificial lights.

The bright lights, aren’t always the right light.