01 Oct Can Prediabetes Affect Your Eyes?
The short answer: Yes, prediabetes can affect your eyes. Blood sugar that runs higher than normal can cause temporary blurry vision, and research has found early blood vessel changes in the retina in some people with prediabetes, before diabetes is ever diagnosed. A comprehensive eye exam can show whether anything has started to change.
Key Takeaways
- Prediabetes means blood sugar is higher than normal but not yet in the diabetes range.
- Higher blood sugar can temporarily blur your vision, and some people show early retinal changes before a diabetes diagnosis.
- A baseline eye exam now makes small changes much easier to spot later.
Maybe it came up at a routine physical. Your A1C was a little high, your doctor used the word prediabetes, and you left with advice about diet and exercise. What probably did not come up was your eyes. That makes sense, since most people connect eye damage with diabetes that has been around for years. Your eyes, however, do not wait for an official diagnosis to start responding to higher blood sugar. Here is what prediabetes can mean for your vision and what you can do about it now.
What Is Prediabetes, and Why Does It Matter for Your Eyes?
Prediabetes means your blood sugar is higher than it should be, but not high enough to be called type 2 diabetes. The American Diabetes Association defines it as an A1C between 5.7 and 6.4 percent, or a fasting blood sugar between 100 and 125 mg/dL. The CDC estimates that more than 1 in 3 American adults have prediabetes, and most of them do not know it.
Your eyes care about this because the retina, the light sensing layer at the back of the eye, is fed by some of the smallest blood vessels in your body. Small vessels are often the first to feel the effects of extra sugar in the bloodstream. Over time, that sugar can weaken vessel walls and change how blood moves through them.
Can Eye Damage Start Before You Have Diabetes?
It can. Diabetic retinopathy is usually thought of as a complication of diabetes, yet the large, federally funded Diabetes Prevention Program found signs of retinopathy in a small share of participants who had prediabetes and had not yet developed diabetes. These early changes are typically mild, such as tiny bulges in blood vessel walls or small spots of bleeding. If diabetes does develop later, leaky retinal vessels can lead to complications such as diabetic macular edema.
Mild does not mean meaningless. Early changes tell your eye doctor and your primary care doctor that blood sugar is already affecting your body. That information gives your care team a reason to watch more closely, and many people find it a powerful motivator to act on their lab results. Blood sugar can affect more than the retina, too. If you are curious how diabetes connects to other eye conditions, read Are People With Diabetes at Higher Risk for Glaucoma?
Can Prediabetes Cause Blurry Vision?
It can, especially when blood sugar runs high for several days in a row. When blood sugar rises, fluid can shift into the natural lens inside your eye. The lens swells slightly and changes shape, which changes how it focuses light. The result can be blurry vision that comes and goes as your blood sugar rises and falls.
This kind of blurring is usually temporary and clears once blood sugar settles. If your vision seems to change from day to day, mention it to both your primary care doctor and your eye doctor. It can also be smart to hold off on new glasses until blood sugar is steadier, since a prescription measured during a spike may not fit you a week later.
Some vision changes should not be waited out. Schedule an exam if you notice:
- Blurry vision that does not clear within a few days
- New floaters, dark spots, or empty areas in your vision
- Night vision that has become noticeably worse
- Colors that look faded or washed out
- Any sudden change in vision in one eye
Keep in mind that early retinal changes from blood sugar often cause no symptoms at all. Feeling fine is not the same as having healthy retinas.
Why Does a Baseline Eye Exam Matter Now?
A baseline is a detailed record of what your eyes look like today. It becomes the comparison point for every future exam. If your blood sugar later crosses into the diabetes range, your eye doctor can compare new images against your baseline and see exactly what has changed and how quickly.
At Total EyeCare, that baseline often includes Optomap retinal imaging, which captures a wide view of the retina in a fraction of a second and usually does not require dilating drops. Optomap is safe for all ages, and your doctor may still recommend dilation if a closer look is needed. We keep those images on file so we can track your retinas year over year. Learn more about our diabetic eye exam services.
Your eye exam can also support the work you are doing with your primary care doctor. For many people, seeing an image of their own retina makes blood sugar numbers feel much more real.
How Often Should You Get Your Eyes Checked With Prediabetes?
Unlike diabetes, prediabetes does not have its own recommended eye exam schedule. For people with diabetes, the American Optometric Association recommends a comprehensive dilated eye exam at least once a year. For adults in general, the AOA recommends a comprehensive eye exam at least every two years before age 65 and every year after that.
If you have prediabetes, a sensible approach is to get a baseline exam soon after you find out, then follow the schedule your eye doctor recommends based on what that exam shows. Other risk factors, such as high blood pressure, high cholesterol, smoking, or a family history of diabetes, may call for more frequent visits. To see how these visits compare, read What Makes Diabetic Eye Exams Different From Routine Eye Exams.
Can You Protect Your Eyes If You Have Prediabetes?
In many cases, yes. Prediabetes does not have to become diabetes, and the same steps that help lower blood sugar also help protect the blood vessels in your eyes. The CDC notes that modest weight loss and regular physical activity can significantly lower the chance of prediabetes progressing to type 2 diabetes. Helpful steps include:
- Following the plan you and your primary care doctor build for your blood sugar
- Keeping blood pressure and cholesterol in a healthy range, since both affect the blood vessels in your retina
- Staying active most days of the week
- Not smoking, or getting support to quit
- Keeping up with eye exams so changes are caught early
Frequently Asked Questions
Can prediabetes cause eye floaters?
Prediabetes is not a common cause of floaters, which are often a normal part of aging. New floaters, especially with flashes of light, should be checked promptly to rule out a problem with the retina.
Will my vision go back to normal if my blood sugar improves?
Blurry vision caused by blood sugar swings usually clears as levels stabilize. Changes in the retina are different, so your eye doctor will monitor them over time.
Do I need a diabetic eye exam if I only have prediabetes?
You may not need the same yearly schedule as someone with diabetes, but a comprehensive exam with a detailed look at your retina is a smart starting point. Your eye doctor can tell you how often to come back.
Can an eye exam tell me if I have prediabetes?
No. Prediabetes is diagnosed with blood tests. An eye exam can show whether blood sugar is affecting the blood vessels in your eyes, which is useful information to share with your primary care doctor.
Schedule Your Visit at Total EyeCare in Billings
Ready to take the next step? Schedule a comprehensive eye exam online or call (406) 656-2898 to get a baseline image of your retinas.
Sources: American Diabetes Association; Centers for Disease Control and Prevention; American Optometric Association; National Eye Institute.