Why you need to see an optometrist if you have diabetes

Geline Mare outlines the importance of annual optometrist consults if you have diabetes.

If you are newly diagnosed with diabetes, welcome. Take a deep breath. Yes, there might be a season of change starting now, but with the support from your loved ones and support groups, formed by veteran diabetes patients, you will get through this.

If you are living with diabetes, you might already know the secondary effects, the pitfalls, you need to watch out for. If this is so, this will be a reminder, a refresher and a motivator to manage your glucose levels and visit all the necessary healthcare professionals annually.

The optometrist consult questions

The following questions should be asked when a diabetic patient visits an optometrist:

  1. What type of diabetes have you been diagnosed with?
  2. When were you diagnosed?
  3. What medication are you currently using? This will be for diabetes, but also includes any other medical conditions.
  4. How often do you check your glucose levels? What is the value on average?
  5. Did you check your glucose level today and what is it?

It is important for an optometrist to understand your glucose level pattern, which will influence the vision and the visual problems that you might experience.

Even though your glucose level might never be considered normal, because of certain factors, having a healthy and stable average helps us determine your vision and visual solutions, should you need anything.

High blood glucose levels

High blood glucose levels have serious effects, but so has fluctuation of your glucose level. A sudden spike can cause unwanted damage and changes in your vision.

Behind the coloured portion of the eye (iris) there is a clear and transparent lens. This lens is responsible for the focusing of images on the nerve layer (retina) so we can see the image clearly.

High glucose levels cause swelling of the lens in the eye, which in effect change the power and curvature of the lens and the image on the nerve layer gets out of focus or blurred.

Optometrists might be able to clear the image by prescribing spectacle correction. But if the glucose level drops, the power of the lens will change again, leading to a different prescription necessary.

Keeping your glucose stable will keep your vision stable. And that will make it possible to accurately determine the power of your visual system.

High and fluctuating glucose levels can ultimately lead to faster changes in the structure of the eye and may cause secondary cataracts, glaucoma and diabetic retinopathy.

Cataracts: hardening of the lens

The lens inside the eye is soft and transparent to let light pass through on to the retina. Think of the white portion of an egg, it is soft and transparent, but as soon as you bake the egg, it becomes white and hard.

Similarly, the lens in the eye becomes white and hard, and that is what we call a cataract, that hardening. But, thankfully it’s a much slower process than with an egg. It becomes more difficult for light to pass through the hardened lens and thus you’ll have blurry vision. Some people compare the vision to a dirty window.

Glaucoma: damage to the nerve layer due to pressure

The eyeball is soft, with no bones, and has fluid inside to keep it in the shape that it should be in. Constantly new fluid is being produced and old fluid is drained out. If the amount of fluid being produced is more than the amount of fluid draining, there will be too much fluid in the eyeball. Unfortunately, the eyeball can’t expand like a water balloon, and the pressure will build up. If that pressure starts damaging the nerve layer (retina) at the back of the eye, we call it glaucoma.

Sadly, the damaged nerve layers can’t be fixed and loss of visual field is permanent. Glaucoma is silent, as there are usually no symptoms to warn you, but thankfully it’s preventable if high pressure is picked up soon enough. If you have high eye pressure, you won’t necessarily get glaucoma (damage). But once you have glaucoma (damage), it cannot be reversed. 


Diabetic retinopathy: damage to the nerve layer due to uncontrolled glucose levels

The nerve layer (retina) at the back of the eye is super important. It is made up of all kinds of nerves, light and colour receptors, and blood vessels. This layer receives the information from our outside world in light form, collects all the data and sends it to the brain for interpretation.

High and fluctuating glucose levels causes changes to the blood vessels that feeds the retina with oxygen and nutrients, which leads to damage to that nerve layer. This damage is called retinopathy.

Applied knowledge is power

All these conditions might not give you initial symptoms and cause for alarm; for this reason, a yearly eye examination is recommended for people living with diabetes.

Remember as Eric Thomas says, “Knowledge isn’t power, applied knowledge is power.” All we can do is give you information and instruction. What you do with it, is the most important aspect. Seek help if you can’t get your glucose levels under control and stable. Don’t give up.


Geline Marè Du Toit got her B.Optom (Hon) degree at University of Johannesburg in 2006 and is now owner and optometrist at EyeLove Optometrist in Roodepoort, Gauteng.

LIKE THIS? ------------------------------------------------

SUBSCRIBE to our FREE Diabetes Focus Newsletter.

Header image by FreePik