While aresfiend is right, the new thermal lenses for profilers don't have the mirrored finish extend all the way across the lense like the old single pane profiler lenses.
This is true.
There's like an explosion of mirror in the center, and it fades to smoke when you get near the edges. Definitely a cool effect for like the red or blue mirrors, but in my opinion not so much with the silver (Then again, I don't really like silver mirror anyway).
You may call it fat, I call it bounce padding.
Once you put them on, people won't be able to see your eyes. It's the same with smoke lens. They look a lot darker on the outside once you put them on. Like others before me said, it's because there's light on the other side of the lens in the picture which is causing you to be able to see through them easier.