Ask the Eye Doctor
VSP® Vision Care, a national strategic partner of the American Diabetes Association, is committed to the ADA's mission and raising awareness about the importance of annual eye exams, especially as it relates to diabetes. Dr. Phelps, a VSP doctor, answers your questions here about eye health and diabetes.
Please review the list of most recently asked questions below and if your area of concern is not addressed, we encourage you to submit a question to our expert – be sure to check back in two weeks to see the answer.
Top 10 Questions & Answers
- Can your vision change day-to-day based on blood sugar levels?
- I'm a 48-year-old male with borderline diabetes. I recently detected a spot in the center of my vision shaped like the continent of Africa. I have always had good vision. Is this a sign of retinopathy?
- What kind of visual problems occur with retinopathy? I was recently diagnosed with diabetes and my A1C is under 7, but sometimes it seems like my vision is cloudy almost like there is a film on my eyes. Is this what retinopathy is? Thank you.
- Why does the presence of sugar in your blood stream weaken the blood vessel, and how does it affect your vision?
- Dear Doctor, I am 55 and have been on insulin 20 years. I developed a blind spot and thought it was because of my blood sugars. My MD said it was more likely due to high blood pressure. Soon after, an optometrist said she saw "cholesterol circles." I am now taking blood pressure and cholesterol medication. My A1C is down to "good" for the first time in ages, and my spots have gone away. I hope I don't blow the second chance to save my sight. Would you please explain how all of these things are related?
- I was told about 4 months ago that I had type 2 diabetes. Yesterday I was told that I have a cataract in one eye. I am 61 years old and my doctor thinks it was brought on by diabetes. Wouldn't I have to have diabetes for more than a few months to have a cataract so soon? Any help you can give me in understanding this would be appreciated.
- I recently had an eye exam, but the doctor did no dilation. It was a ten minute exam to find what looked clear for a prescription for glasses. Now I have the glasses, but every few hours my vision fluctuates. I have started to use eye drops over the counter because my eyes get itchy and burn. What can I do for this and what does VSP cover?
- I have diabetes and need an eye exam. What kind of eye doctor should I see and how can I find one?
- I went to see my doctor due to a sudden change in my eyesight, and I was diagnosed with diabetes. I began having severe headaches and vision changes. Are the headaches and vision changes related? Will my vision change again or return to normal? Thank you in advance for any information you can provide me with.
- I get this bright spot in my eye that's like a flash bulb going off, and I cannot see clearly out of that eye for 10 to 30 minutes. It's always in one eye. This is happening three to four times a week. Do you know what may be causing it?
1. Can your vision change day-to-day based on blood sugar levels?
Yes it can, although it's more common for vision to fluctuate over a period of days or weeks, rather than each day. When your blood sugar levels start to average either higher or lower, as best measured by a change in your A1C level, your vision's focus or prescription can change. This is due to a swelling or thinning of your natural crystalline lens.
2. I'm a 48-year-old male with borderline diabetes. I recently detected a spot in the center of my vision shaped like the continent of Africa. I have always had good vision. Is this a sign of retinopathy?
Borderline diabetes is not a well-defined term. We usually speak of pre-diabetes, or glucose intolerance when a person has not quite met the criteria for a diagnosis of diabetes. Some people with diabetes can keep their blood sugar under good control without medication, but it is still called diabetes. A general answer to your question would be that spots in your vision can be something as simple as a floater or it could be something more complicated, such as a retinal lesion, macular degeneration, a macular hole, or possibly diabetic macular edema. If someone called my office with this symptom, I would schedule a dilated eye exam right away.
3. What kind of visual problems occur with retinopathy? I was recently diagnosed with diabetes and my A1C is under 7, but sometimes it seems like my vision is cloudy almost like there is a film on my eyes. Is this what retinopathy is? Thank you.
Mild to moderate retinopathy causes no vision problems whatsoever. If retinopathy gets to the level where you have swollen or damaged tissue, you can have a noticeable loss of vision. If you're starting to notice a change in your vision due to retinopathy, you've already waited too long. Loss of vision or distortion would be a more likely symptom of retinopathy than clouded vision. It can also be just a floater or a beginning cataract. You should get a dilated eye exam right away to find out for sure what's going on.
4. Why does the presence of sugar in your blood stream weaken the blood vessel, and how does it affect your vision?
High blood sugar can cause temporary changes to vision because it can cause the lens to swell. High sugar levels can also cause damage to the internal membrane of the capillaries, which weakens them. If the retinal capillaries are damaged, you won't have any visual symptom unless significant damage has already taken place. This is one of the reasons why you need to make sure you get your eyes checked annually. Good blood glucose control and timely laser treatment can minimize permanent damage in many cases.
5. Dear Doctor, I am 55 and have been on insulin 20 years. I developed a blind spot and thought it was because of my blood sugars. My MD said it was more likely due to high blood pressure. Soon after, an optometrist said she saw "cholesterol circles." I am now taking blood pressure and cholesterol medication. My A1C is down to "good" for the first time in ages, and my spots have gone away. I hope I don't blow the second chance to save my sight. Would you please explain how all of these things are related?
If you develop any problem with your vision, you should get your eyes checked right away. Both high blood pressure and diabetic retinopathy can eventually cause significant damage to the retina and blind spots. People with type 2 diabetes are more likely to have "corneal arcus" (cholesterol circles), because they're more likely to have high cholesterol. Corneal arcus does not usually go away even if you do get your cholesterol under control, however the arcus does not affect your vision. Hypertensive retinopathy can reverse itself with good control, and if you didn't show any signs of diabetic retinopathy, you have not lost your "second chance." Controlling your A1C, blood pressure, lipid levels and getting regular dilated eye exams is how to minimize your risk of permanent vision loss.
Note: High cholesterol, diabetes, and high blood pressure are commonly associated in "metabolic syndrome."
6. I was told about 4 months ago that I had type 2 diabetes. Yesterday I was told that I have a cataract in one eye. I am 61 years old and my doctor thinks it was brought on by diabetes. Wouldn't I have to have diabetes for more than a few months to have a cataract so soon? Any help you can give me in understanding this would be appreciated.
I've sent four people in for cataract surgery this week, one of which is a healthy 59-year-old person. It's a simple procedure regardless of how it was brought on. Early onset cataracts can be associated with diabetes, but those without diabetes can also get early onset cataracts. The actual cataract surgery time is usually about 15 minutes, and you most always go home the same day with better vision than you had the day before. If a person has significant diabetic retinopathy and cataracts, more risk benefit analysis is normally done before scheduling cataract surgery.
7. I recently had an eye exam, but the doctor did no dilation. It was a ten minute exam to find what looked clear for a prescription for glasses. Now I have the glasses, but every few hours my vision fluctuates. I have started to use eye drops over the counter because my eyes get itchy and burn. What can I do for this and what does VSP cover?
Most of the time dilation is part of a comprehensive exam unless there's a medical reason not to do it. VSP covers a comprehensive eye exam, which includes dilation. If your vision fluctuates it's more likely due to dry eye syndrome or tear film issues. Itchy burning eyes can be related to allergies, which can affect tear film. I would recommend a medical eye exam for ocular allergies. There are some fairly good over the counter drops for allergies, but it would be best to consult with an eye doctor who shows more of a medical interest in your eye condition. VSP does have a list of eye doctors who do comprehensive eye exams. A call to VSP would let you know what your individual coverage would be.
8. I have diabetes and need an eye exam. What kind of eye doctor should I see and how can I find one?
The American Diabetes Association recommends a person with ongoing diabetes have an annual dilated eye exam by an ophthalmologist or optometrist who is knowledgeable and experienced in diagnosing the presence of diabetic retinopathy and is aware of its management. I definitely agree with this recommendation. You can visit VSP Vision Care's web site, www.vsp.com, to find a qualified private-practice eye doctor near you.
9. I went to see my doctor due to a sudden change in my eyesight, and I was diagnosed with diabetes. I began having severe headaches and vision changes. Are the headaches and vision changes related? Will my vision change again or return to normal? Thank you in advance for any information you can provide me with.
Yes, blood sugar variations can affect your vision within a short time. Changes in your crystalline lens can occur due to these variations. If the vision fluctuations are due to blood sugar levels and there's no diabetic retinopathy, it is usually reversible and can return to normal. Once your diabetes is brought under a stable control, the vision should stabilize and there should be no long-term effects. Severe headaches can be the result of many different things. They're not necessarily related to vision, but they can be. High blood sugars can sometimes be associated with headaches, but you should talk to your primary medical doctor about the headaches.
10. I get this bright spot in my eye that's like a flash bulb going off, and I cannot see clearly out of that eye for 10 to 30 minutes. It's always in one eye. This is happening three to four times a week. Do you know what may be causing it?
The symptoms you're talking about are commonly associated with ocular migraines, but can also be due to many other factors such as blood flow problems to the retina or visual cortex. I would recommend a dilated eye exam with a visual field test, and a follow up general medical exam to figure out the actual cause.
Don't see your question answered? Check the archive of previously answered questions.
MEET THE EYE DOCTOR
Roger Phelps, O.D. is a Certified Diabetes Educator and an optometrist with more than 30 years of experience. Based in Ojai, Calif., Dr. Phelps has type 1 diabetes, and frequently travels the country delivering speeches and presentations on preventing diabetes-related blindness.
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