Most people experience changes in vision gradually over a period of months or years. They start moving their reading material closer or farther away in order to see the letters or find themselves struggling to see clearly when driving at night. These kinds of changes are common, especially as people age.
Diabetes: Diabetes patients are at risk of a condition called diabetic retinopathy. Diabetic retinopathy is caused by low blood sugar that results in damaged blood vessels in the retina, the part of the eye that senses light. Damaged blood vessels can cause swelling of the part of the retina called the macula, and can contribute to macular degeneration. Diabetic eye degeneration can cause blurred and/or spotty vision and can lead to blindness if not properly diagnosed and treated.
Stroke: Sudden blurred vision is also a symptom of strokes. Strokes impede blood flow in the brain and can cause blurry vision, double vision, or sudden loss of sight. Other stroke warning signs include dizziness, drooping facial muscles, confusion, balance problems, difficulty speaking clearly and loss of feeling in one arm.
Brain tumor: A tumor in any part of your brain can cause pressure to build inside the skull. That can cause many symptoms, including blurred vision. Other warning signs of a brain tumor include unusual drowsiness, headaches that won’t go away, seizures, nausea, and vomiting.