Just because you think you will go blind does not actually mean that you will go blind. In a similar vein, if you look at the moon tonight and think that it will explode in the next five seconds, it probably won’t.
It is a good thing that your doctor will not give you another exam. For practical purposes, your insurance probably covers only one exam per year, so your eye doctor would not be able to do it anyway unless you were going to pay out of pocket.
Your doctor is also probably aware that some people have anxiety concerns about their health, and OCD can surely be focused on health. OCD fears can lead a person to get checked out by many different doctors, to want numerous tests for disorders or diseases that are extremely rare, or to spend hours on the Internet researching signs and symptoms.
Some therapists even ban their patients from using the Internet for a period of time during treatment so that they will not try to look up more disease information.
So it is not a good idea to try to convince your doctor to give you another exam because the relief that you will feel from that exam will be only temporary, until you obsess about your next symptom and want another exam to confirm that you are free from any disease.
It would be better to seek treatment about your health obsessions so that you can learn how to handle your fears instead of needing constant reassurance from medical professionals.