You may also get blurred vision when you start insulin treatment. This is due to shifting fluids, but it generally resolves after a few weeks. For many people, as blood sugar levels stabilize, so does their vision. Longer-term causes of blurry vision can include diabetic retinopathy, a term that describes retinal disorders caused by diabetes, including proliferative retinopathy. Proliferative retinopathy is when blood vessels leak into the center of your eye. Besides blurry vision, you may also experience spots or floaters, or have trouble with night vision.