My son has had diabetes for three years. Recently, we went to the optometrist who said that my son has astigmatism in both eyes. His vision is changing constantly because of his fluctuating blood sugars. He actually needs glasses when he is high, but when he’s average, he doesn’t. This is affecting his school work. Is there anything, besides tighter control, that can be done?

It is important to know that blood sugar changes can create a shift in vision. With high sugar, the shift can go either way (vision can become more blurry or even less blurry). Therefore, you cannot monitor blood sugar by what vision is doing. Taking a blood sample is the only way to monitor sugar. Diabetes aside, uncompensated astigmatism (no glasses) is characterized by vision shifts or fluctuations while attempting to focus. You mentioned that his vision is changing constantly. If you mean that his vision is shifting focus, this would be more the astigmatism and not the sugar. Vision shift from only sugar is not that rapid. It is more likely characterized by a day to day shift or early morning to late morning etc. He is most likely having a shift in vision from both. As a rule, if the patient’s vision is below the minimum needed to perform a task safely and successfully, be it driving or reading, and, the vision can be improved with glasses, then glasses should be prescribed. The patient may need to get a subsequent pair once the sugar is stabilized, or, may need multiple pairs, if control is difficult. Glasses are a visual aide, and, as such, may be temporary, permanent, or variable. The patient cannot be left in a blurred state.

CAG