I remember when I first started wearing glasses again as an adult (had them for viewing the chalkboard in HS). I put them on and felt like I was walking like an ostrich as my steps didn't feel like they were actually hitting the floor. Who knew my depth perception was that bad? When you hit the age for multifocals, it's just great.
Also it kind of depends on how bad your eyesight is. My peripheral vision is not bad since my prescription is not terrible (like 0.75 in one eye and 1.75 in another). I don't wear my glasses running or doing other sports. If you're prescription is a lot worse then it can be unsettling taking them on and off and seeing anywhere besides through your glasses.