Thanks for the help...
Go to an ophthalmologist. ASAP.
Unfortunately at our age vision problems begin to occur.
My mother got macular degeneration.
There are treatments that help eye disease, earlier the better.
https://www.mayoclinic.org/diseases-conditions/optic-neuritis/symptoms-causes/syc-20354953
Read this. Here is the optimistic take home.
“Most people who have a single episode of optic neuritis eventually recover their vision without treatment. Sometimes steroid medications may speed the recovery of vision after optic neuritis.”
But that’s assuming optic nerve inflammation is the problem.
Did your friend go to an opthamologist?