The simple truth is I wear glasses and I hate it. Before I would go on to the mountain with my Spy goggles and no glasses. This ended badly. So I gave these Smiths a shot. They fit great and the vents work as advertise in keeping everything fog free. However, there is always a however, when you stop moving, your glasses start to fog up. The goggles aren't the problem, I would imagine that any goggles designed to be worn over glasses will perform similarly. The only time Im not moving is when I come to the bottom of the run, I then just wear the goggles round my neck, problem solved. Thats a small price to pay to be able to see the details in the snow. I might give the antifog stuff designed for Scuba diving.