There has many reasons which would cause the blurry vision here, and the disease parts of eyes are different. Inflammation is the most common reason of vision blur. The inflammation has two ways to cause, by virus and the dry eye is the common term of xerosis of conjunctiva. It’s the eyes symptom of tear film's pathological change, thus the cornea and conjunctiva without normal moist and feel dry. It will lead to blurred vision in a long time. The reasons of the cause of dry eyes could be inflammation and immune system abnormal as well as lack of vitamin A. The two former reason may caused by infection, while the last one is caused by the nutrient condition. Myopia, hyperopia, astigmia, amblypia etc will also lead to vision blur. Eyes muscle hurt by physical crash, chemical burning, glaucoma will also lead to the same symptom. Other parts body disease of circulation and metabolism will affect the eyes blood circulation too. Old people are easy to get cataract when eye aging. You must think about your own situation, or go to doctor to see the details if your eyes got disease or only lack of nutrients to nourishing.