An abrupt and dramatic loss of vision may be a sign of a problem with the blood flow to your eye or your brain. Immediate medical attention can prevent serious damage and may even save your life. Even if your vision gets better quickly, it might still be a warning of a stroke or the beginning of a migraine headache
Graves' disease causes your thyroid gland to release too many hormones, which can lead to this problem. It also may cause diarrhea, weight loss, and hand tremors. Medication or surgery can help control the amount of hormones your thyroid makes, but they won't cure the underlying disease -- and may not help your eyes.
This can be a sign of diabetes, which causes too much sugar in your blood. If it isn't well managed, you may get diabetic retinopathy (when tiny blood vessels in your eyes leak blood and other fluids). You may have blurred vision and find it hard to see at night. Doctors can use a laser to seal the leaks a…