Blurry vision could mean you need to take better care of your diabetes and manage your blood sugar more strictly. Of course, it may also mean you're getting older and simply need a pair of reading glasses. Blurred vision is one of many possible diabetes symptoms, but it can be difficult to determine the cause by yourself. How do you know when to talk to your doctor, optometrist, or ophthalmologist?

If blurred vision develops quickly, it could be temporary, and a sign that your blood sugar is much too high. This is because high blood sugar makes the lens of your eye swell - and a change in the lens alters the way you see. If you get sudden-onset blurred vision, you need to check your blood sugar and get it back into your target range as soon as possible. You should already know your target range from talking to your doctor, and you should also know how to address high blood sugar. If you're not sure, ask your doctor.

Sudden blurred vision can also indicate very low blood sugar levels - and once you correct this, your vision should return to normal.

If your blurred vision develops gradually and persists, there are a few things you should know. Diabetes may cause damage to the eyes over time, and that damage can be permanent. For this reason, you should have a full dilated eye exam soon after your diagnosis and regularly thereafter.

If you have both blurred vision and eye pain, you should see your doctor and have your eyes examined. You may also want to call your doctor if you have persistently blurred vision that worsens over time. This may indicate longer-term damage.

For more on diabetic eye complications:

Antibiotic May Help Treat Diabetic Eye Disease
Eye Exams with Diabetes: Why They’re Important
Cataracts and Glaucoma: The Other Diabetic Eye Complications