I had 20/20 vision for most of my life. I never had any problems with the test for Visual Acuity.
I don’t have the exact date when my vision started deteriorating but now I have two sets of glasses. I still can barely see. When they show you two slides and say “which is better?” neither one is. I can’t tell the difference between the two during the tests.
Perhaps in the future my vision will return. I have thought about using contacts but I have trouble putting them in. If I wore contacts I would get the Halloween type where they make your eyes appear slightly outrageous.