My mother has some kinda feeling in the head, not headache & she sometimes feels pain in the right eyeball & sometimes blurring of vision in right eye?

Giant cell arteritis. This is a diffuse inflammatory disease that primarily involves the cranial branches of arteries originating from the aorta. The disease frequently causes unilateral headaches, jaw pain, eye pain and blurred or double vision. This is a serious condition and needs medical attention asap.