Well, generally speaking, high blood sugar can affect your eyesight. According to some researches, high blood sugar can cause problems in the retina, and this part is collectively called micro vascular abnormalities. And you should know that the small blood vessels develop microaneurysms and leak blood, and then new blood vessel growth can achieve. But on the other hand, when you get high blood sugar, these blood vessels will become weak and leak. What is worse, these leaks can cause irreversible damage to the retina and permanent vision loss. So you should just be more careful about your sugar intake. Also, high blood sugar can lead to blurred vision, double vision, even eye floaters too.