You'd toss them off with burning eyes.
We see things by photons (light particles/waves) passing through the cornea (lens) of your eye, with an image formed on your retina. Rods and cones (2 different types of cells) in the retina tell you how bright and what color things are, respectively. HOWEVER, they both require a certain amount of light to work (rods less than cones, that's why when it's dark you rarely see color.)
Night vision goggles work in a similar way, but instead they have a small electronic that works just like the rods in your eyes, but is far more sensitive. It can pick out the details that are too dim for your natural eyes, and displays the image on a screen that's on the eye-side of the goggle. This electronic is so sensitive though, that if you turn on the lights it floods (overloads) the imaging cell, and you get blasted with a vision full if incredibly bright light.