Since the beginning of the plandemic, that's now almost 2 years, I wore a mask once to vote in a primary and I almost did not go because of the mask mandate. I wore my fishing gator mask for like 3 minutes in total. A fishing gator is a cloth tube that is just to meant to keep the sun off one's face ears, and neck. It however is a mask, so they can't say anything.
That said, I wear N95 masks all the time when I am creating dust in sanding, mowing the lawn, blowing leaves etc., and special masks when using chemicals like 2 part isocyanate paints (deadly poisonous). I take them off during breaks to clean my face. I don't understand how people can volunteeringly wear a mask all day like it was a pair of paints or a shirt, breathing in their stink breath, sweat, and mold.
All of that said, if an eye doctor wants me to wear a mask that they provide while I am under his face, I would do it, it is no different than wearing a mask to blow leaves. If the operation takes hours, change the mask a few times, you are not paying for it. Go into the doctor's office with no mask and have them provide you with what they like. No big deal.