High blood sugar can damage blood vessels and the nerves that control your heart. People with diabetes are also more likely to have other conditions that raise the risk for heart disease:

• High blood pressure increases the force of blood through your arteries and can damage artery walls. Having both high blood pressure and diabetes can greatly increase your risk for heart disease.
• Too much LDL (“bad”) cholesterol in your bloodstream can form plaque on damaged artery walls.
• High triglycerides (a type of fat in your blood) and low HDL (“good”) cholesterol or high LDL cholesterol is thought to contribute to hardening of the arteries.

When this type of eye damage happens, it’s called diabetic retinopathy. It can lead to poor vision and even blindness.