Thank you all for the information.
From rpinrd:
Great. I have always wondered why a dimmer switch on the side view mirrors was not standard equipment.
I doubt that I can get my '95 S-10 retrofitted, but it will be a definite feature on my next truck.
From Duck Duck Goose:
Yup, well that is what scared me. Which is why I wanted some testimonials from dopers if they had experience.
Off to the optometrist I go, then.