One detrimental aspect of Graves' is Graves' ophthalmopathy. The eyes bulge because inflammation cells and inflammation goop fill the eye socket. Inflammation goop infilterates eye muscles, disturbing their co-ordinated movements resulting in double visison. Predinison, a cortisone drug and radiation are considered to be two effective treatments depending on the doctor's recommendations. Surgery is yet another method of decompressing the eye socket and realigning eye muscles.
Eyelid surgery can rid the patient of constant tearing.
Smoke and smoking aggravates grave's disease, so should be avoided. Your father's doctor, however is the best judge of his medical situation. Talk to him about specifics of your father's health problem.