Mercury Vapor bulbs and coil types are totally different things. The coil types are basically florescent bulbs in a compacted spiral form. MVBs are a totally different type of bulb.
I have yet to see a case of a MVB damaging a reptiles eyes, but I've seen many cases of the coil types causing damage.
Yep, coil bulbs usually are JUST sold as producing UVB. MVBs are like your average house bulb, except they provide UVB in a safer package, along with heat.
I like tube UVBs, they are safer that coil bulbs too...