What is the worst vision you can have and still pass a driving test?

20/200: If your vision is 20/200 or worse, you are not allowed to schedule a driving test. 20/200 means that what you see something at 20 feet looks like what someone [with normal vision] sees at 200 feet. Hope this helps!

Check your state: "visual acuity screening standard is 20/40 or better with both eyes together, no worse than 20/70 in the poorer eye. Drivers who fail the vision screening are referred to a vision specialist. Drivers with visual acuity of 20/200 or worse may not be licensed to drive. Drivers may use bioptic telescopes for driving, but may not use them to meet the vision standard".

Varies by State: Most states set a limit of 20/40 in the best eye for their limit. There is some variation by each state. Check with your department of motor vehicles for the rules in your state.