What is a major effect of damage to small blood vessels in diabetes?

Damage to small blood vessels, a common complication of diabetes, primarily affects the eyes, kidneys, and nerves. This microvascular damage is particularly significant in the context of vision loss. When small blood vessels in the retina are damaged, a condition known as diabetic retinopathy can occur. This condition can lead to vision impairment and, in severe cases, blindness. The disruption of normal blood flow can also result in swelling and leakage of fluid, contributing further to vision problems.

The other options do not directly relate to the specific consequences of small blood vessel damage in diabetes. For instance, weight gain, slow metabolism, and increased energy levels are not primary outcomes of this microvascular complication and do not capture the serious implications of vascular damage on eyesight.