Eye Conditions


One of the most common eye conditions in over 40s, cataracts are typically the result of the natural aging process. A cataract is cloudiness in the natural lens of the eye which results in hazy or blurred vision. The good news is cataract removal is a safe and effective treatment and one of the most common eye procedures performed in New Zealand.

In most cases, cataracts are simply the result of aging. Protein in the lens clumps together making it cloudy, which prevents the lens from creating a sharp or focused image on the retina. The cloudy lens scatters light rather than transmits it to the retina resulting in blurry or hazy vision.

If you’ve ever worn glasses you’ll know how frustrating it is to have smudges and marks on the lens which degrade your vision. This is similar to the effect of a cloudy natural lens/cataract.

During the early stages of cataracts there may be little impact on vision. Usually, the process of the lens clouding occurs very slowly, so people will not even be aware they are developing cataracts unless they have regular eye check-ups. 

As cataracts develop patients will experience blurry vision, changes in contrast, glare, and haloes/starbursts around lights. These symptoms can lead to difficulty driving, reading and recognising faces.

A cataract will not go away by itself, and for many people, will eventually cause vision to deteriorate to the point where it will absolutely compromise quality of life. For a significant cataract, surgery to remove the cloudy lens and replace it with a clear, artificial intraocular lens is the only treatment.



Cataracts are most commonly caused by the aging process. In some cases they are associated with an injury to the eye, from medications such as steroids, or from diseases such as diabetes.



Thanks to modern surgical techniques cataracts are totally curable. Cataract surgery is performed under local anaesthetic. Patients can expect improved vision a few days after surgery, and to fully recover within four weeks.



There is a common misconception that cataracts are a film on the outside of the eye – this is not the case. A cataract is opacity (cloudiness) of the lens inside the eye.

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Click here to find out more information about what to expect after cataract surgery.


What exactly is a cataract?

Our eyes consist primarily of water and protein, and as we age, the eye’s protein can clump together and cloud the lens. In a healthy eye the protein is spread evenly, creating a clear lens, allowing light to pass onto the retina at the back of the eye. As light passes through the lens, a sharp and focused image is produced on the retina. 

This image is processed through the optic nerve to the visual system of the brain.

If the lens is not able to focus light onto the retina because of clumps of protein, it is not able to produce a sharp image. The clouded lens scatters light rather than transmits it to the retina resulting in blurry or hazy vision, a symptom known as opacification.

It may help to think of the natural lens in the eye as being clear like a window in the lounge of your house. With a bad cataract this window becomes fogged and the view outside is difficult to see.  

What causes cataracts?

Natural aging is the most common cause of cataracts. However, there are other less common causes for cataracts, these include:

Congenital – While it is rare babies can be born with cataracts, or these can develop in children in the early years.

Traumatic – Cataracts may result from a significant injury to the eye. 

Secondary – Cataracts can result from the use of some medications, the most common example being steroids. Some general health conditions may cause cataracts – the most common is diabetes. Cataracts can also form due to many other eye diseases such as uveitis (inflammation in the eye) or be a side effect of other eye surgeries/procedures.

Is there anything I can do to prevent cataracts?

While cataracts are typically part of the natural aging process, there may be some actions you can take to prevent the development of cataracts. These include an annual eye check-up that allows your optometrist to monitor any early signs of cataracts (as well as any other conditions such as macular degeneration or eye disorders). Some lifestyle factors may increase the risk of cataracts, such as smoking, excessive drinking and excessive exposure to sunlight. People who have diabetes or have experienced previous eye injuries are also at a greater risk of developing cataracts.

Are cataracts painful?

Cataracts form slowly over time and do not cause pain or discomfort. Because of this, most people will be unaware they have a cataract until it starts to affect vision.

What are the symptoms of cataracts?

Cataracts do not tend to impede vision in the early stages. As cataracts develop, patients can experience several symptoms, including:

  • Blurry or hazy vision and changes in contrast
  • Difficulty driving at night due to haloes/starbursts around lights
  • Sensitivity to light (particularly very bright sunlight)
  • Difficulty reading 

At some point the cataract can become so dense it will become difficult to carry out everyday tasks and will severely compromise quality of life. 

How are cataracts treated?

Cataracts cannot be treated with glasses, contact lenses or laser eye surgery. It will not go away on its own – surgery is the only treatment

Cataract surgery is one of the most commonly performed and most effective surgeries in New Zealand. Advances in technology have meant that almost all patients will have their vision restored following cataract surgery and, in some cases, will have reduced reliance on glasses.

What does cataract surgery involve?

Cataract surgery involves removing the eye’s natural lens and replacing it with a clear artificial lens that focuses the light clearly onto the retina again to restore vision. A keyhole incision is made in the front of the eye to reach the cataract. The cataract is broken up, removed, and the replacement intraocular lens (IOL) is inserted. The surgery is typically performed under local anaesthetic and carried out by one of our eye specialists in an operating theatre at a dedicated eye care facility.

What can I expect after cataract surgery?

Prior to your surgery, your eye specialist will talk to you about your visual requirements and use technology to help you choose which strength and type of artificial intraocular lens (IOL) is best suited to achieve your vision goals. Because of this, you can expect to experience improved clarity of vision post-surgery and depending on the type of IOL chosen, reduced need for glasses. 

Cataract surgery gives patients more independence too. For example, many patients regain improved eyesight to the point that they can regain their driver’s license. You can also expect improved colour vision, more confidence to drive at night and often reduced need for glasses.

Is cataract surgery safe?

Cataract surgery techniques and equipment have been refined over the last 40 years to the point where it is now regarded as one of the safest and most cost-effective operations in the world. The sheer improvement in your quality of life after restored vision is well worth the investment! As with all surgery there are risks however. Your eye specialist will fully discuss these risks with you before you proceed to surgery.