Yes, it is bad for eyes. Diabetes could bring eye problems in many ways. First of all, let me give you a briefing about diabetes. Diabetes happens because your body stops producing one kind of hormone called insulin, or producing less insulin. Insulin could help digest glucose in your body, transferring glucose to energy. Without enough insulin, there will be too much glucose in your body which affects the normal work of all other part of your body. Then how does it affect your eyes? The most common eye condition that caused by diabetes is involved with the blood vessels, which supply the retina. This kind of condition is called diabetic retinopathy. When diabetes is not under control, the high blood sugar caused by diabetes will impact the lens of inside the eye. As time goes by, your vision could get cloudy, which is called cataract. It is really very bad for eyes. If you are suffering from diabetes, I suggest you go to the doctor for help. Meanwhile, you must control your diet and control your weight. One friend of mine, her father is a diabetes patient. After he adopted a surgery to shrink his stomach, he lost 40KG in two months. And his blood sugar level gets normal since then. So I think it is important to control your food intake and weight. Hope you could get well soon.