What is an example of a bad score on a visual acuity test? When are you bad enough to need glasses to drive?

20/40 or Worse. A distance vision test of 20/40 or worse will disqualify you on a dmv physical here in california. They differ state to state, but i believe they are the same. So 20/40, 20/50, 20/60, etc would be examples of worsening vision. 20/20 is perfect. It is what you see from 20 feet / what a normal person sees from.