What is the effect of your blood sugar level on vision?

Blurry vision. Fluctuation blood sugars can result in a change in the vision. The vision may become blurry because if the sugars are high excess sugar moves into the lens of the eye and water follows, and the lens will change shape. It can take several months for the vision to stabilize once the blood sugars are under control.
A few different ways. First, fluctuating blood sugars can cause the lens inside the eye to swell and shrink, causing vision to blur in and out. This can often normalize once the sugars have become stable. Second, fluctuations over months or years can lead to early cataract formation. Third, elevated sugars over years can lead to permanent vision loss from damage to the retina (film of the eye).