I live on the Gulf side in Florida. I don't ride on the streets here. Only on the Pinellas Trail. There are many sight challenged seniors here. The best Florida riding, IMO, is from Gainsville and north towards the panhandle. Bike Florida sponsers rides in Florida every year, and I found those areas to be the best. But no specific rides, sorry.
34 miles one way. There is another just a bit longer trail north of Tampa. Withlacoochee trail. Both are very similar, fully paved. Pinellas trail is more urban, but a good ride. Withlacoochee more rural and fewer intersections.