The better diabetes is controlled the less likely significant eye problems will occur. High levels of sugar in the blood due to lack of the hormone insulin can cause problems over time. For example, the small blood vessels and capillaries of the body may become leaky.

When the blood vessels supplying the back of the eye leak, blood and fluid can enter the surrounding retina and damage the cells which detect light. In the long term, diabetes can lead to some other eye problems, including cataract, glaucoma and diabetic retinopathy.