Cataract Surgery

The good news is that cataract surgery is both safe and effective. With the help of a replacement lens, it is possible to regain the vision quality you had prior to cataracts.

Cataract surgery is both safe and effective - it is possible to regain the vision you had prior to cataracts.

Cataracts related to ageing (50+) are the most common type, but cataracts can also result from hereditary factors, diseases (such as diabetes or hyperthyroidism), medications (such as long term use of steroids) or injury. 

Understanding cataracts

As we grow older, the eye’s natural lens can stiffen, harden and begin losing its clarity, forming a cataract. Your vision appears as though you are looking through a frosted window.

Cataract symptoms

  • Cloudy or blurred vision

  • Sensitivity to light and glare

  • Poor night vision

  • Dull or faded colour

  • Frequent changes in glasses prescription, not providing clear vision 









About cataract surgery

Cataract surgery is a safe, effective way to improve your vision.

Dr Kent usues a micro surgical technique to remove a cataract, promoting faster visual recovery. Dr Kent forms a tiny incision (3mm) on the side of the cornea to probe the cataract using high frequency sound waves (phacoemulsification) to break up the cataract for removal from the eye.

Dr Kent then inserts an intraocular lens made from silicone, plastic or acrylic where the cataract once was.

The surrounding membrane is left intact and because of the size and location of the incision, stitches are rarely needed, and the eye heals rapidly. 

Not all intraocular lenses are the same and no single lens works best for everyone. At your consultation with Dr Kent at Fendalton Eye Clinic we will discuss your visual and lifestyle requirements to ascertain the most suitable intraocular lens for you.

 CES1 logo      SX logo

Dr David Kent performs cataract surgery at the  state-of-the-art  Christchurch Eye Surgery in Papanui Road.
The purposely built ophthalmic surgical facility was opened in 2014

Fendalton Eye Clinic is an Affiliated Provider to Southern Cross Health Society for selected services

Zeiss AT LISA trifocal IOL (Diffractive)

Zeiss AT LISA trifocal provides good unaided distance, intermediate and near vision


Improved vision means precise vision. Something ZEISS stands for over 160 years.

This is why astronauts relied on ZEISS quality to take pictures of the first moon landing.

Google Earth sees more with ZEISS precision lenses.  Hollywood captures more with ZEISS

camera lenses. Whenever directors and camera crews shoot beautiful, unforgettable films,

ZEISS camera lenses are often involved – The Lord of the Rings.

Diffractive IOLs have three focal points for distance, intermediate and near vision.

They split light rays to the three focal points using diffraction grating technology.

With a unique asymmetrical light distribution of 50 %, 20 % and 30 % between far, intermediate

and near foci, AT LISA trifocal is able to provide more satisfying and predictable visual outcomes

across three areas rather than the traditional 2 zone focusing multifocal (like the two zone ReSTOR

multifocal and Tecnis Multifocal). Due to the intermediate addition of +1.66, the ZEISS AT LISA

tri focal significantly improves visual acuity at the intermediate distance, enabling you to feel more

comfortable performing daily activities in this vision range.


Advantages:  Good unaided distance, intermediate and near vision. Best option for complete spectacle independence.    

Disadvantages:  Halos around lights at night time. Starburst may also occur. Some patients experience mild glare but it usually resolves.


Monofocal IOLs for monovision

Monovision is where one eye can see clearly in the distance and the other eye is intentionally made short-sighted

so that it has either near reading vision (full monovision) or intermediate (arms-length) distance vision (limited monovision).

Fedalton Eye Clnic 8157


Monovision is a compromise because the distance eye does not read without glasses and the near eye cannot see in the distance.
There may still be times when top-up glasses will be required such as:
•    Driving a car in poor light conditions, particularly when it is raining.
•    Prolonged reading, as it can be tiring to read with only one eye.

The main advantages of monovision are that using modern aspheric monofocal IOLs or toric IOLs usually gives good optical quality

without halos, ghosting or glare. With monovision you can still wear glasses that correct both eyes for distance or both eyes for near vision

and achieve good optical quality. Achieving monovision with monofocal IOLs or toric IOLs is less costly than using either multifocal, segmented

asymmetric Oculentis IOL’s or any type of accommodating IOLs.

Advantage:  Can see distance with one eye and near with the other.  Can be corrected for distance or near with spectacles. Safe if there is any other eye disease.    

Disadvantage:  Reduced binocular vision. Adaptation to monovision may not happen in some, reading speed is slower than bilateral multifocal IOLs. Most end up

needing glasses for some tasks.

IOLs for Astigmatism

Corneal astigmatism is a common eye condition that causes vision to be blurry or distorted due to an irregular (slightly oval)

shape of the cornea. This irregularity prevents the eye from properly focusing light on the retina. If you have cataract and

astigmatism, you may have the option to correct the cataract only, or for spectacle-free distance vision, your doctor may

recommend a toric intraocular lens. When the lens with cataract is replaced, your astigmatism is corrected, giving you better

distance vision than prior to surgery.

Monofocal IOL with astigmatism correction

Monofocal IOL with astigmatism correction
The ZEISS AT TORBI® 709 M / MP provides the most up-to-date technology to correct more patients’ astigmatism.

The lens platform enables implantation through a micro incision, easy rotation during surgery and excellent stability

after surgery for more precise outcomes.

Mulifocal IOL with astigmatism correction -  suitable for patients with astigmatism who wish to reduce their

dependence on glasses

The ZEISS LISA Tri Toric 939MP  IOL  is the latest trifocal innovation from ZEISS, not only designed for distance and

near vision like traditional MIOL’s in the market place, but also for the intermediate zone. The introduction of the intermediate

add eliminates the dead spot and subsequent need for glasses for tasks like computer work that are noted with more traditional

multifocal lens designs. The trifocal design by ZEISS also addresses issues such as unwanted visual phenomena and reduced

image quality to enable excellent functional vision in all lighting conditions.

Monofocal IOLs for emmetropia

Monofocal IOL - to optimise distance vision -with the Zeiss CT Asphina

If you don't mind wearing glasses after cataract surgery, a monofocal lens implant usually is used.

Often, only part-time use of reading glasses are needed after surgery with monofocal IOLs.

The most common type of intraocular lens has a monofocal optic that provides a single corrective power calculated for good distance vision. It is normal that with monofocal IOLs, for some tasks such as reading and close work, you will still need glasses.

Advantage:  Clear distance vision, no significant halos or glare. Safest option if there is other eye disease.    

Disadvantage:  Total  presbyopia, glasses required for intermediate and near vision

How can we help you?

Short-sightedness Long-sightedness Astigmatism Cataract Presbyopia
Short-sightedness Long-sightedness Astigmatism Cataract Presbyopia
Short-sightedness Long-sightedness Astigmatism Cataract Presbyopia
Short-sightedness Long-sightedness Astigmatism Cataract Presbyopia
Short-sightedness Long-sightedness Astigmatism Cataract Presbyopia
Before After