I worked for a commander/flight surgeon who studied circadian rhythm. Mostly, he was interested in sleep cycles since that was more pertinent to pilots, and full spectrum light was a possible way to keep night shift workers awake and alert.

Please note that UV light can damage your eyes, whether it's from the sun or from a bulb.

I wonder how SAD affects people who can't see: if it DOES affect them and whether light works for them. I wonder if the light has an effect other than the visual and we just notice the visual component because we CAN see.