Ghost uses a frame-applied material that reflects both infrared and visible light. In low light environments they will maintain your privacy on cameras using infrared for illumination and also block 3D infrared facial mapping during both day & night. The visible light reflection can make you anonymous in images/videos using a flash in low light.
Ghost is $170 (US, I'm assuming). Not great but not bad for a wicked cool looking pair of sunglasses. Considering Ray-Bans are around $200 (and, no offense, look like they're from Tesco), and that Ghost are privacy focused, I'd say that price seems not that bad. Still high, though.
If they can target the underlying architecture of the models like nightshade does, it will actually be quite hard to deal with for the surveillance companies.