A *Good* set of field glasses...
Coupled with a good observer* permits one to resolve that Saturn is oval. Galileo described the planet as having "ears" through his primitive telescope.
When I was younger, I had 40/20 vision (I could see at 40' what the average eye could see at 20'). Now I'm in my Forties I "only" have 20/20 vision. Still the only person in my family who doesn't need glasses. (But my night vision isn't what it used to be)