With the coming of the Redemption, all physicians will find themselves unemployed. The reason for that is that all people will be healed and will stop falling sick. It follows that doctors will need to get re-training in some other professions. The first ones to be healed will be the blind as it says in the Torah — "When G-d comes to heal His people, the blind will be the first ones."
The Almighty will restore their eyesight so they will merit to see the light of the Redemption. So what, after all, will the eye doctors be doing with the coming of Moshiach? There will be huge lines of the formerly blind outside their offices and they will be rubbing their eyes in astonishment not believing that they are able to see again!
The only thing left for the doctors to do will be to calm them down and assure that their eyesight has indeed returned.