Blurry vision

Diabetes symptoms sometimes involve eyesight. High levels of blood sugar pull fluid from the body's tissues, including the lenses of the eyes. This affects the eyes' ability to focus. With diabetes treatment and better control of blood sugar, the eyes' ability to focus usually returns and blurry vision goes away.

If it's not treated, diabetes can cause new blood vessels to form in the retina — the back part of the eye. That can damage other blood vessels. For most people, these early changes don't cause vision problems. However, if the changes aren't found and they get worse, they may lead to vision problems and, eventually, blindness.