Hello,
Cause of dizziness is commonly Vertigo or Meniere's disease. He can get an
audiometry test done to confirm if he has ear problems that is leading to dizziness and difficulty in co-ordination. Dizziness and
double vision can also be caused by eye problems like
astigmatism or aniseikonia that may cause complications like
disorientation, eye strain, headache and balance disorders.
Since your dad has a history of having shingles, double visions may be neuro-ophthalmological complications involving the
optic nerve in H. zoster patients. You are suggested to get him tested for shingles in the eye and get him treated at the earliest. In the meantime, if diabetic, control his blood glucose level at all cost. Maintain his BP and electrolyte system of the body. He should take home made balanced nutritious food. Avoid addictions if any.
Take care. Hope I have answered your question. Let me know if I can assist you further.
Regards,
Dr. Nupur K., General & Family Physician