I very much prefer natural light to artificial light. I've wondered, regarding lighting windowless areas: Why don't buildings put natural light collectors ("wi

I very much prefer natural light to artificial light. I've wondered, regarding lighting windowless areas: Why don't buildings put natural light collectors ("windows") on exterior surfaces, and use light redirectors ("mirrors" and maybe "fiber") to shunt the light to places that otherwise lack it. The light could be output through the same fixtures that host artificial light sources. (Sensors and dimmers on artificial light sources could compensate for variations in natural light.) It would be much more pleasant than artificial light and it would save energy. Perhaps the ROI isn't high enough.