At 76, I always wear tinted (day) or clear (night) reader safety glasses when I drive. (Owing to an unfortunate incident several years ago - apparently airbags and metal frame nose posts don't mix very well.)

I don't like bifocals, and after experimenting with various diopter strengths, I found that 1.75 was a good compromise that allowed me to both see the dashboard instruments, and read distant road signs.