Eye Conditions Related to Diabetes

What is diabetes?

In diabetes, the body cannot cope normally with sugar and other carbohydrates in the diet. This may be due to a lack of insulin or to the insulin that is present not working effectively.

Diabetes can start in childhood or in later life. It can affect many parts of the body, including the eyes. There are two types:

Type 1 diabetes
This type of diabetes commonly occurs before the age of 30 and is the result of the body producing little or no insulin. It is controlled by insulin injections and so is also referred to as insulin dependent diabetes mellitus (IDDM).

Type 2 diabetes
This type of diabetes commonly occurs after the age of 40. The body does produce some insulin but either the amount of insulin produced is insufficient, or the body is not able to make proper use of it. This type of diabetes is generally controlled with diet or tablets and so is referred to as non-insulin dependent diabetes mellitus (NIDDM). Some people in this group however will require insulin.

Why are eye examinations important for people with diabetes?

People with diabetes are at a higher risk of developing eye conditions that can affect vision. These conditions may be present before you realise that your vision is affected.

If your diabetes is well controlled, then you are less likely to have problems. Most sight loss due to diabetes can be prevented, but it is vital that it is diagnosed early. Therefore, regular eye examinations are extremely important.

How can diabetes affect the eye?

Diabetes can affect the eye in a number of ways.
These include:
  • Temporary blurring
  • Cataract
  • Diabetic retinopathy

Temporary blurring
This may occur as one of the first symptoms of diabetes or at any time when the blood sugar level is not well controlled.

When the blood sugar level changes, water moves in or out of the lens of the eye. The change of shape of the lens results in a variation in the ability of the lens to focus light on the retina. Blurred vision is the result. This blurring will clear without treatment when your diabetes is brought under control again.

A cataract is a clouding of the lens of the eye. Light cannot pass through the clouded lens to the retina at the back of the eye. The vision becomes blurred or dim.

Cataracts commonly develop as people get older. In diabetes, cataracts tend to develop at a younger age.

Diabetic retinopathy
The most serious eye condition associated with diabetes involves the light sensitive membrane at the back of the eye called the retina. More specifically, it involves the network of blood vessels within the retina. Read more about this important condition called diabetic retinopathy.

When to schedule an eye examination

When you are first diagnosed with diabetes, you should have an eye examination:
  • Within five years of the diagnosis if you are 30 years old or younger
  • Within a few months of the diagnosis if you are older than 30 years

An eye examination should be performed at least once every year. More frequent examinations may be required if diabetic retinopathy is detected. Pregnant women with diabetes need to be examined at least once in each trimester.

If your glasses need to be checked it is important that your blood sugar level be stable for several days prior to the examination. Rapid changes in blood sugar level can cause fluctuation in vision in both eyes and incorrect glasses being prescribed.

You should have your eyes checked promptly if you have changes in your vision that:
  • Only affects one eye
  • Last more than a few days
  • Is associated with floaters

Important points to remember:

  • Early diagnosis of diabetic retinopathy is vital
  • Have an eye examination every year
  • Don’t wait until your vision has deteriorated to have an examination
  • Most diabetes related eye problems can be treated with laser if detected early
  • Don’t be afraid to ask questions about your treatment

Change the text size


Suite 15, Mater Medical Centre
76 Willetts Road
Mackay QLD 4740


(07) 4942 3301


(07) 4942 9815
Vision loss is largely preventable
If you have diabetes, it is important to realise that, with improved methods of diagnosis and treatment, only a small percentage of people will have serious vision problems.

Research into diabetes related eye conditions is continuing and treatment is constantly improving.

Good control of your blood sugar level and regular eye examinations will significantly lower your risk of vision loss.
Fig 1. Anatomy of the eye.
Image - Anatomy of the Eye


The information provided here is for general education only and should not be construed as individual medical advice. For advice relevant to your particular situation, please speak to Dr Hornsby.