Diabetes and Vision

Diabetes is a chronic disease associated with abnormally high levels of glucose in the blood. Around the world it causes significant sickness and possibly early death, but it is also one of the leading causes of blindness and visual impairment in working age people. A person with diabetes has 25 times the risk of blindness compared to someone without the disease.

Commonly diabetes is due to :

    1. Inadequate production of insulin. Called type I Diabetes.

    2. Inadequate sensitivity of cells to the action of insulin. Called type II Diabetes.

    3. Diabetes while pregnant. Called Gestational Diabetes.


Unfortunately, diabetic eye disease is often asymptomatic in the early stages. This means that people don’t know that they are developing issues with their eyes. We believe it is important for a diabetic to get their eyes tested annually. Most diabetes-associated vision loss is preventable. This is helped by early detection.

To prevent diabetic eye complications it is important to have a healthy lifestyle, which includes diet and exercise. Also if blood pressure is not controlled adequately, this can also hasten diabetic eye disease. It is also important to report any sudden changes in your vision. 

In New Zealand we have a very good health system. The retina of diabetics are screened via trained nurses to find any problems. If they find anything untoward, then the person is referred to an ophthalmologist for care. The retina is the sensitive lining of the eye; to use a camera analogy it is like the film in our camera. If there is damage to this sensitive organ, it can mean significant difficulties in the way the eye sees. 

Interestingly, diabetes is no longer our leading cause of blindness in working age people (it is now genetic eye conditions). This has changed due to the improved care we can offer our patients – unfortunately, this is causing a strain on our public health system.

Diabetes of the retina affects the blood vessels, and we are fortunate enough to be able to view these easily by looking into your eye.

There are some other things that diabetes can do to your eye, which wouldn’t be screened for under our public health system. For example:

Dry eyes – this can range from being mildly annoying and needing to blink a bit more often; to using eye drops frequently; to developing vision limiting infections.

Hypoesthesia of the cornea – ulcers can develop on the front surface of someone’s eye as the nerves aren’t working correctly. 

Small pupils – which can affect the clarity of your distance vision. 

Glaucoma – this is an eye disease where the eye is damaged by pressure inside the eye.

Cataracts – these happen to everyone eventually, but are a problem for diabetics younger in life. Cataracts are the lens inside your eye going cloudy or opaque, making your vision blurry and needing surgery to correct it. 

Diabetic retinopathy – these retinal changes can range from mild to severe.  This the most common complication from diabetes, at least a third of diabetics get this.

Asteroid hyalosis – this is where there are floaters in the jelly inside the eye.

Anterior ischaemic optic neuropathy – the optic nerve can become damaged.

Cranial nerve palsies – the nerves that the eye uses for normal function can become damaged and can cause a range of problems, such as double vision.

Orbital mucormycosis – this is a fungal eye infection.


As you can see, there are lots of ways diabetes can affect the eye and regular eye checkups are important for people who are diabetic. There are a range of eye issues which can happen from diabetes. The best advice we could give you is to get your eyes routinely tested, as early intervention if there are any problems can be save your vision.