Hah, I'm already there in my 40s! I'm seriously considering getting a strap for my glasses - right now I just hook them into my shirt, but they'll occasionally fall out when I bend over for something, and it's only a matter of time before they break or go into a sewer.
When I was in my 20s, this was absolutely not a problem.
When I hit my 30s, I started wearing glasses instead of contacts basically all the time, and it wasn't a problem.
Now that I'm in my 40s, I'm having to take my glasses off to read a monitor and most things that are closer than my arm's reach.