Ophthalmologists can detect early signs of type 2 diabetes by observing retinal microvascular damage.

“the canary and the coal mine believe it or not of microvascular damage is within the eyes so a good opthalmologist is generally the first doctor to tell when a person is on the road to type two diabetes because by looking at the retina and by looking at the capillaries in the back of the eye they're actually able to do something that no one else gets to do in the body right like we don't look directly at the vascular system elsewhere in the body and they get to do that they get to shine a light directly onto those capillary beds”