Cataracts Karu puata kore

The lens of your eye works like the lens of a camera. It focuses 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.

Cataract symptoms depend on the location and the severity of the cataract. You may not have any symptoms from cataracts or know that a cataract is developing.

As a cataract grows, you may notice:

• cloudy, blurry, hazy, foggy or filmy vision
• the pupil of your eye looks cloudy
• decrease in distance vision — such as when reading or watching TV
• improved near vision of close objects
• changes in the way you see colour — black and white seem dull, or grey and yellow
• glare from bright light — for example, problems driving at night 
• double vision (diplopia) when looking with one eye
• needing to change your glasses prescription often.

Cataracts 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 (for irregular heartbeats).

If you think you might have a cataract, see an optometrist or ophthalmologist (specialist eye doctor) for an eye examination.
You can also:

• call or visit your healthcare provider
• call Healthline for free advice 0800 611 116

Find an optometrist

You can find optometrists online:

• Optometrists — Healthpointexternal link
• New Zealand Association of Optometristsexternal link

Cataracts can be treated at any stage. There is no need to wait for the cataract to 'ripen' before it can be treated.

• If your cataract is not affecting you very much, your optometrist can monitor your eye to see how it progresses. They can also let you know if your vision is good enough for you to drive.
• If your cataract is more severe, your optometrist or healthcare provider can refer you to an ophthalmologist (specialist eye doctor) to see if surgery will help you.

If you need cataract surgery

Once vision loss is affecting your normal lifestyle, cataracts are treated with surgery.

When considering surgery, your ophthalmologist will ask about your overall health and any other eye conditions such as:

• damage to the optic nerve at the back of your eye (glaucoma)
• disease that affects the cells that feed the back of your eye (age-related macular degeneration)
• diabetes damage.

Eligibility for surgery

Cataract surgery is available through the public health system. There is a points system to decide who can get it. The scoring is based on your vision and the effect your cataracts are having on your life. You need to have a certain score to go on the waiting list for publicly funded surgery.

Cataract surgery process

This is a simple procedure usually done under a local anaesthetic. Surgery is usually painless and very safe.

Cataract surgery removesthe cloudy lens by making a small (keyhole) cut in your cornea at the front of your eye. The surgeon then replaces it with a c lear artificial lens (also called an intra-ocular lens).

The artificial lens can also correct other vision issues such as short-sightedness (myopia), long-sightedness (hyperopia) or blurred vision because of the shape of the cornea or lens in the eye (astigmatism).

Complications from surgery

Major complications of cataract surgery are uncommon — they happen in around 1 in 500 people. Complications can include:

• internal eye infection (endophthalmitis)
• retinal tear (or detachment) or swelling (macular oedema)
• night glare
• chronic swelling (inflammation)
• when the cataract is not completely removed (retained lens fragments).

The risks of complications are less than leaving the cataract to get worse and cause blindness.

After surgery for cataracts

You can usually go home the same day. You will need to use eye drops for several weeks after surgery.

You may notice the following effects that usually disappear within 1 to 2 weeks:

• your eye may feel tender and light-sensitive for a few days
• colours may appear brighter
• your eye may look bloodshot or there may be small red marks on the white of your eye
• you may have small floating spots or a flickering effect in your vision.

• Wear sunglasses or a hat to block sunlight. Use wrap-around sunglasses that are labelled as 100% protective against UVA and UVB rays.
• Stop smoking.
• Eat a balanced diet with a mix of different coloured fruits and vegetables. This gives your body the antioxidants it needs to be healthy.
• Have regular eye examinations with an optometrist if you are over 60. Optometrists and your usual helathcare provider can refer you to an eye doctor and surgeon (ophthalmologist) if you need to see one.

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