[Dancing frogs]

UV does not pass very well through window glass. To allow UV, a screen portion under the lights will work, as will Solacryl, Acrylite OP-4, and Plexiglas UV-T. Starphire glass may also work, but I'm not too sure of that.

 

[Dancing frogs]

Neither really "need" (at least not like an iguana needs) UV to do pretty well, however there has been theories that the UV is beneficial to the frogs.
If you read the original post, Beeswax specified that he wanted his lid to allow UV.

 

[Dancing frogs]

I've tried both the fiberglass and the metal screen, and the metal lets more visible light through (you can see the difference), so I'm guessing it will allow more UV through as well.
Take this link for some info on UV, including percentages of UVA, and UVB that common materials allow to pass.
http://www.anapsid.org/uvtable.html
Though not entirely ff proof, if there is only the strip under you're light fixture for screen, not many will survive long enough (near the heat of the bulb) to get into you're house.