Consider this a public service announcement, of a sort. The Sheflogger and I enrolled our five-year-old in swim lessons, both to burn off what seems to be an unlimited amount of energy (that he steals from us, but that's another rant) and for the sake of safety. Swimming saves lives.
Littleflogger didn't like traditional spaghetti-strap goggles much, but when we hooked him up with Frogglez it was problem solved. These goggles have a wide, comfortable neoprene headband that takes a lot less fiddling then traditional straps. The hook-and-loop adjustment is infinitely variable within its limits, and is easy enough that kids quickly figure out how to do it themselves.
Your kids will eventually move to traditional goggles, but for a year or three Frogglez will be the go-to goggles that make both your lives easier.