Pyro Vision Goggles Lens Re-Texturing?

[Jeromius]

I've been fiddling with the goggle's texture and I've been trying to re-texture the lens of the pyro vision goggles to no avail. I simply made the entire texture a single colour to see if it's even possible. Turns out the everything except the lens was coloured. So what should I do? Is it something with the phong? should I simply remodel the lens entirely?

Here's a pic: http://steamcommunity.com/sharedfiles/filedetails/?id=434460524