HealthInfo Waitaha Canterbury

Overview of cataracts

Tirohanga whānui ki te karu puata kore

A cataract is when the clear lens in your eye becomes cloudy. This can lead to reduced vision.

The lens of your eye works like the lens of a camera. It focuses the light onto the retina at the back of your eye. If the lens is no longer clear, light cannot pass through it and your vision becomes cloudy.

Cataracts are one of the most common causes of reduced vision but are easily treated. They usually happen with ageing, but there can be other causes.

Things that can increase your risk of getting a cataract include:

• a family history of cataracts
• smoking
• diabetes
• an eye injury
• high levels of UV sun exposure
• some long-term medications, such as steroids and amiodarone.

Symptoms of cataracts

You may not have any symptoms from a cataract.

As a cataract grows, you may notice:

• cloudy, blurry, hazy, foggy or filmy vision – reading and TV are not perfectly clear
• improved near vision (close objects)
• changes in the way you see colour – black and white things seem dull, or grey and yellow
• problems driving at night and glare with bright light
• double vision when looking with one eye
• a frequent need to change your glasses.

Diagnosing cataracts

If you're concerned that you might have a cataract, see an optometrist or ophthalmologist (specialist eye doctor) for a detailed eye examination.

Treating cataracts

Once vision loss is affecting your normal lifestyle, cataracts are treated with surgery. They can be treated at any stage. There is no need to wait for the cataract to "ripen" before it can be treated.

Surgery involves removing the cloudy natural lens and replacing it with a new clear lens.

This is a simple procedure usually done under a local anaesthetic.

Reducing your risk of getting cataracts

• Wear sunglasses or a hat to block UV sunlight.
• Stop smoking.
• Have a balanced diet with a good mixture of different coloured fruits and vegetables. This gives your body the antioxidants it needs to be healthy.
• To make sure you discover any cataracts early, have regular eye examinations with an optometrist if you're over 60. Optometrists and your general practice team can refer you to an eye doctor and surgeon (called an ophthalmologist) if you need to see one.

  HealthInfo recommends the following pages

• New Zealand Association of Optometrists – Cataracts

  A factsheet with an explanation of what cataracts are, their symptoms and their treatment.

• American Academy of Ophthalmology – What are cataracts?

  These pages explain what cataracts are, who is at risk, diagnosis, treatment and surgery. They include animated videos.

On the next page: Treating cataracts

Written by HealthInfo clinical advisers. Last reviewed March 2023.

Sources

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