If you experience numbness of the ears, accompanied by numbness and tingling of your arms or legs, you may have severe and uncontrolled diabetes. According to the Mayo Clinic, diabetic neuropathy occurs when uncontrolled blood glucose levels cause damage to nerves. This damage is usually focused on the nerves of the legs or the feet, but other body systems can be affected as well. Mononeuropathy is a type of diabetic nerve disorder that targets a nerve of the face, torso, or leg. When the face is affected, the individual may suffer temporary vision problems or facial paralysis.