The driving ban for failing eye test already exists.
My licence has been downgraded to a B1 because of sight issues. The ridiculous thing is, it is encumbent on me to inform DVLA of any further deterioration. My eyesight could go down one point, there is no way that I could detect such an small drop without a test. If I'm involved in an accident I could face jail.
The reality is, I need an eye test every day to avoid such a scenario! Obviously this isn't viable.