30 Year Old Son Is On Celexa Generic, Citalopram For

30 year old son is on Celexa generic, Citalopram for last few months. Is noticing that after he exerts himself in sports especially, he loses the peripheral vision in both eyes. Not sure if this is a side effect of the drug. He says things seem to go back to normal 30 min or so later. He just lost his insurance and will be on Medicaid until he gets employment somewhere that offers insurance, so he is trying to get his other doctor to see him as soon as possible, IF he will see him.
I told him he cannot just stop the medication, but how do you "wean" off of it if he cannot see someone soon?