In my case, I am in Florida for a week selling my house... I decided to renew my license yesterday morning online. I was denied and told I needed to go to the local HSMV office, so I went. I was made to take a vision exam and a signs test because I got a speeding ticket 34 months ago (although prior and post I've had a perfect driving record). For the record, I am perfectly healthy, in my mid 20's, and have corrected 20/20 vision (20/40 uncorrected which is the cutoff in florida for not having a restriction on your license).
I guess they don't want to risk the bad press if an elderly person should die while they spend 3+ hours waiting in line. (I was able to at least escape and get a sandwich)