Yes, just as you technically can watch a 3D movie with both eyes open, but also:
No, not unless you switch your hand back and forth between your eyes REALLY fast (like, at least, 60 times a second), or blink that fast.

If you cover one eye, and have the other one open, you'll still see the two different images, flickering between them. It will basically look blurry. The key point is that the glasses switches back and forth between the eyes, in sync with the projector/TV switching the two images.

It's basically this effect: https://i.stack.imgur.com/CGbUh.gif, but much faster (and a video, with moving subjects, etc)