Red flags The following findings are of particular concern: Sudden change in vision Eye pain (with or without eye movement) Visual field defect (by history or examination) Visible abnormality of the retina or optic disk HIV / AIDS or other immunosuppressive disorder A systemic disorder that could cause retinopathy (eg, sickle cell anemia, possible hyperviscosity syndrome, diabetes, hypertension) Interpretation of findings Symptoms and signs help suggest a cause (see table Some Causes of Blurred Vision).