beta blockers

I have had two open heart surgeries to replace my heart value due to chemo.  The doctors want me to take beta blockers but I have very serious reactions to them, i.e., eye focus & vision problems, wobbling & dizzyness where I can't even walk.  I can't function on these meds.  Since most people can take beta blockers with little or no side effects, my doctor thinks I'm making up the seriousness of my side effects and shouldn't be having these problems.  Any help?  So far the doctor hasn't really said what would happen if I didn't take the drugs.  Thanks.

[Momto3]

Do you get ocular migraines (visual disturbances, but not necessarily with a headache)?  

[dardee10]

No, just can't focus to see very good.  Now I'm taking digoxin and after I take it at night the symtoms (symptoms) start up again.  Same as when I was on the beta blockers but a little different side effects.  I'm better in the afternoon after the medicine as worn off from the night before.  Thanks.