I too need to wear my glasses. I'm so nearsigthted I literally can't read the namepatch on my own work shirt without my glasses.
I went with the elastic strap for awhile because my glasses would fly off. I guess I improved over time because I haven't had to wear the elastic strap for a few years now.
I'd say if the ukemi at your dojo is rather vigorous to definitely go with the strap. I really liked the
Croakies type. They just slide on and have a flat neoprene strap with no hard parts to land on.
Bronson