When I saw somebody put on sun-scream under UV-Light only on Youtube, his skin was black. I had an epiphany. I already knew, that we see only a very small band of light. But what if some parts of my organism developed to use other bands of the spectrum? For them I am living in the dark most of my day.

I actually have no Idea if this is the case - but regarding our biology the science has still many, many unknowns (when I watch Michael Levin, I know that we are still right at the beginning of our journey). So what happens if some systems depend on other bands of the spectrum than visible light?

The preventative solution would be to simulate the Sun-Spectrum as close as possible:

Tbh, I have no idea about these things and I am not sure, how much time I am willing to invest. This is just an idea. 5778 K is kelvin and I have no idea what this diagram wants to tell me. But some (grow) lights have a spectrum in their marketing material:

The scale is much different. Most of the infrared spectrum is missing. And some of the UV. I have the gut feeling that different sources are additive. So I would need a spectrometer to get the light spectrum of outside and a bunch of different light sources from UV to Infrared to match the cure of outside as close as possible.

So: Get an spectrometer, measure, buy, adjust, repeat until I match the outside spectrum as close as possible. Maybe block the light which the sunscreen blocks.

Here is another image I found afterward. Here are more information and numbers