What Causes Dizziness And Eye Strain In A Diabetic?

My mother is a Type-2 diabetic patient with high blood pressure and osteoarthritis. Her age is 53. Her BP and diabetes are normal on checkup but recently her head keeps on spinning and eyes get strained leading to discomfort. Also, few days back her eardrums kept on banging continuously. After consulting an ENT, this problem got cured. What might be the problem with her? Can you tell please.