Stefan makes a good point about distinguishing between the various forms of UV light. At first, we were specifically talking about UVC, which is the most dangerous type (but least common) because it has high-energy, short wavelength emissions. It's very effective at killing waterborne microbes but also has deleterious effects on vertebrates.
"Blacklights" emit in the near UVA and slightly into the visible light spectrum. These are different from UVB lights. As far as I've read, Vitamin D is produced when the skin is exposed to UVB, so I'm not sure what the UVA provides (besides heat). Perhaps someone could clarify?
Both UVA and UVB can create thiamine dimers in the DNA (i.e. inappropriate bonding), leading to replication errors and tumors/cancer. UVA and UVB can also stimulate cells to secrete "prostaglandins," which suppress the immune system, lead to premature aging of the skin (wrinkles), and can cause a whole lot of other maladies.
I've attached a link to a World Health Organization website that talks about the effects of UV light on several health-related endpoints. It is very brief but has links that provide more information. One endpoint includes eye diseases as a result of UVA (blacklight) exposure.
Personally, I think it's a cheap and simple matter to use Infrared bulbs to produce heat and supplement a reptile's diet with calcium plus vitamin D instead of using the UV-type bulbs. The UV bulbs are probably fine to use "sparingly," but I wouldn't expose myself to them for several hours at a time, day after day. In my opinion, it's not worth the risk.
Finally, I believe that calcium supplementation is necessary (particularly in the absence of UV light), and most Ca supplements come fortified with vitamin D. Therefore, I don't believe additional vitamin D from UV lighting is prudent. Vitamin D isn't water soluble; it's fat soluble and can accumulate in fatty tissues. It becomes toxic at high concentration. I don't want to imply that UV light cannot or should not be used, it just comes with known risks. Since I've never owned a lizard/anole and know little about their physiology, please don't use my advise toward their well being. Best,
Rick
WHO | Health effects of UV radiation