It'd be nice, wouldn't it, if there was a formula you could just plug data into, and get an answer? But again, it varies. I'm sure the bulb and the fixture influence, as would any plastic diffusion screen you'd put in front of the light. There was a warehouse store we go to, that prior to them changing their lighting in the store, I'd experience all sorts of weirdness after visiting there. We went there one rainy evening to get new tires on the car, and shopped. We were there for over two hours. A bit after we got home, I broke out with a rash, and did the malar thing on the face that "blistered" the worst I'd had up until that point. I missed several days of work from the flare. We couldn't figure out what happened to me, until a couple years later, they re-did their store, including the lighting, and they put up signs stating that their lighting was now "UV-Safe". I'd get a milder reaction from work when they had the old row flourescant lighting in there. Most of this
article I don't know about, but the "Other Conditions" section, I can attest to, both with the lupus and the migraines...
"There but for the grace of God, go I."
"... His mercy endureth for ever."