After looking into it, I've decided against UV for the sole reason that there's evidence to suggest that it does indeed cause eye problems.
Now, do these problems stem from the UV, or from any form of bright lighting? I want to have a light source for two reasons. Firstly, so that the geckos know what time of day it is (lights on during the day, lights off at night), and secondly so that I can actually see what's happening in the viv without having to reach for a torch!
Would a 60w "regular" bulb, for example, be safe to use? I know people use red bulbs for warmth, so would a clear bulb be suitable simply for providing light? Will this source of light not pose problems for the Leos eyes?