Sleeping badly? Feeling down? Waking up tired? 
Lacking concentration? Blurry vision?
Maybe you spend too much time indoors, where the light is often too weak during the day and too bright in the evening to keep us healthy and happy! 

In the long run, this leads to sleep, mood, energy and health problems.

Try good light!

Good light is the right light at the right time.

Good light is daylight (outside or inside near a window),

or indoor electric light that mimics daylight.