Right, sunlight contains UVA and UVB and the UVB is what creates vitamin D. An indoor light that outputs UVB could be dangerous, the equivalent of laying outsi

Right, sunlight contains UVA and UVB and the UVB is what creates vitamin D. An indoor light that outputs UVB could be dangerous, the equivalent of laying outside in the sun all day, every day. It would also quickly degrade many materials in your house. UVA would trigger photosensitive eyeglasses turning them dark. Sperti makes a vitamin D lamp and it has a five minute timer and comes with UV blocking goggles (not sure what intensity it is relative to the sun) which suggests significant risk. So you may not want any forms of UV inside your home. Many windows these days have glass formulated to block UV to protect your rugs, drapes, and furniture. I'd question whether anyone would want the IR spectrum from an indoor sun-light also. I think what most people would want would be a high CRI light that has enough blue to trigger the brains time keeper. A bright indoor daylight-like light will make everything look very stark though (black shadows, objects brightly lit so you see all the fingerprints, scratches, and dust everywhere.) Your eyesight may degrade faster if you are constantly in brightly lit areas also. You may find that your autistic friends stop visiting you (or ask you to turn the lights off.) A lot of people who built A-frame houses with floor to ceiling windows at the end of the house found out that all that light entering 1) makes the house really hot 2) interferes with reading, watching TV, and using computers 3) fades their furniture and rugs. Even without the UV, bright indoor light has some issues, though it certainly can brighten dark spaces.