Think of some thing simple like need for correct spectacles if you need them or migraine or high blood pressure, which not only blurs your vision but also gives you headaches. This can be hereditary and certain things precipitate it like some food, stress etc.Other possibilities are dry eyes or neck ache, which laptops and computers users get a lot due to wrong positioning and heat, generated by the computers. Keep laptop away from you and take care of your own positioning.Only if you excluded these problems, you could think of something sinister as brain tumour. The best way to exclude that would be to get CT or MRI scan of the brain. Discuss this with your ophthalmologist.