Bariatric or gastric bypass surgery is an effective treatment option for patients with morbid obesity-associated diabetes. Bypass surgery leads to an immediate improvement in diabetes and related complications. The overall theme of the current project is monitoring changes (reversal or progression) of diabetic peripheral neuropathy using imaging of front part of the eye (cornea). In vivo confocal microscopy of the cornea is a unique painless method enabling direct observation of nerves in the living human eye. The first part of the project (CHOCS Study) aims to determine changes in the eye after bypass surgery which may provide an objective measure to assess reduction of peripheral neuropathy. The second part of the project (TOFU Study) involves re-reviewing diabetic patients (fully evaluated 5 years ago) to determine corneal changes and their association with diabetic peripheral neuropathy, and overall longitudinal relationship with diabetes control.