Hi, Cymbalta or duloxetine is a kind of antidepressant which is known to cause many side effects such as nausea, headache and dry mouth.These are common side effects but one less common but possible side effect is what you had probably experienced i.e. blurred vision or hazy feeling. Lexapro (escitalopram) is used for the maintenance treatment of major depressive disorder after Cymbalta .But it is till now not known to cause hazy feeling or blurred vision which you suspect. Therefore, you must contact a psychiatrist and your surgeon to have a better clarification on the matter. One thing is definite that your condition has least related to your thyroid surgery. Thanks!