I used to have perfect vision.
But like most folks over 40 I've found I now need glasses, age related astigmatism. For reading it's now essential. My distance vision is OK, but I much refer to wear my glasses basically all the time, everything is so much sharper. So I wear em on the bike.
But, when I'm hill walking, or I'm out on the bike and the rain starts hammering down. I tend to pull over and take em off. The crunch comes when I end up with water droplets on my glasses, combined with the water on the visor, it just becomes a nightmare to see.
Yup I've had it with misting up too, on the visor and on the glasses, ziltch visibility, pulled over and took em off.
So first question is how well can you see without your glasses. Is it essential or just preferable that you wear em?