Is it unusual to be 50 years old and not need glasses?

I was exactly same at 50. I didnt need glasses until 53. Still only use them for reading small or badly coloured print (ie. Yellow on red or red on black). I have very mild regular knee pain (Barely 1/10 on the pain scale). Turned out to be advanced arthritis. Go figure. Still fit and active in a physically demanding job. Look after yourself like you would a tool or car. Preventative maintenance (eat reasonably, do some exercise) will help prevent or ease problems later. But, unfortunately it is like everyone says, its downhill after 50.