Correct me if I'm wrong but wether or not a lens is 2 layers (thermal) or not doesn't actually have much bearing on their anti-fog properties. Pretty much everyne I know who has had a pair of Invisions says that they are useless when it comes to fogging up and they are dual layered.
What makes the difference is the coating on the lense. From stuff that I've been hearing, the lenses in the Profilers rarely have any problem with steaming up. These lenses are only single layer and the coating on them is a hell of a lot more hard wearing than that of the one on the pro-flex or invision.
What makes the difference is the coating on the lense. From stuff that I've been hearing, the lenses in the Profilers rarely have any problem with steaming up. These lenses are only single layer and the coating on them is a hell of a lot more hard wearing than that of the one on the pro-flex or invision.