We perceive approximately 90 % of our surroundings with our sense of vision. Our surroundings must be adequately lit. As we age, our visual capacity deteriorates which is why older people (55+ years) require more light to see well and without straining their eyes.
A room is well lit when its luminosity reaches approximately 300 lux; for a workstation, this value should read 500 lux. When working intensely with paper documents and to recognise filigree structures, up to 750 lux are necessary to avoid straining our visual capacity.
Colder light lowers the level of melatonin, a sleeping hormone, in the blood and thus increases performance. Therefore, it is recommended to use a blue-white light in the morning. Around lunch time, it should be white-yellow. When your day at work is coming to an end, light in the red-yellow spectrum has a soothing effect.
You should ideally be seated at a 90° angle, i.e. in parallel to the window. The light should not reflect in the screen. It is also less stressful for your eyes if you do not look directly into a light source.