Published 13 Sep 2022

Cataracts, much like wrinkles on our skin, are a natural part of aging. Understanding your risk of cataracts and treatment options can help you determine the best strategy for management.

What are cataracts?

In a healthy eye, light rays enter through the clear cornea, pupil and lens and are focused directly onto the retina, the light sensitive tissue lining the back of the eye. The retina is responsible for converting light into electrical signals which travel through the optic nerve to the brain, where they are recognized as images.

Cataracts occur when the lens inside the eye becomes cloudy. The cataract hinders light entering the eye and causes it to scatter, creating blurred vision. It’s like looking through a foggy or frosted window, so things appear blurry and less colourful. Cataracts develop gradually over years, and it is when cataracts interfere with activities such as reading, watching television, or driving, that surgical intervention is recommended. An optometrist can assess if your vision can be improved with the use of glasses or contact lenses. The goal of cataract surgery is to help you see better when glasses or contact lenses no longer help.

What causes cataracts?   

Cataracts are the result of several factors, age being the most common cause. Proteins within the lens start breaking down naturally around the age of 40, which creates the gradual clouding of the lens. Other causes may include:

  • Genetics
  • Certain medical conditions such as diabetes
  • Penetrating traumatic eye injuries
  • Certain medications such as corticosteroids
  • Damaging ultraviolet (UV) light, thus not protecting your eyes from the sun
  • Smoking

What are the early signs of cataracts?

Early signs can often be mistaken for ‘aging’ and include diminishing ability to see in poor light. A person with cataracts may start to reach for a reading light and may find light glare difficult when driving at night.

What factors can influence timing of cataracts surgery?

There are many factors that will be discussed with your optometrist prior to seeing a specialist. These may include:

  • Lifestyle factors – you want to walk away from your surgery with a better quality of life than before
  • Driving requirements – the legal vision requirements may speed up the decision to have cataracts surgery
  • Risk of falls from impacted mobility due to poor vision
  • Any risk of early onset Alzheimer's or dementia, it may be a better experience to have the surgery while cognition is better
  • Access to surgery including elective surgery wait lists 

Cataract surgery

You will undergo a procedure prior to surgery called Biometry, where your eye is measured to determine the most appropriate power of the lens (intraocular lens / IOL) to be implanted into your eye, after the cataract is extracted. It is recommended that if you are a contact lens wearer, to not wear these in the week prior to your appointment.

During the surgical procedure, a tiny incision is made into the side of the cornea and the top of the cataract. Ultrasound is then used to liquefy the lens material, which is then vacuumed out. A foldable lens implant (IOL) is then carefully inserted into the lens bag called a capsule, where it unfolds and remains in place. After the procedure, a shield is then placed over the eye to protect it overnight. You will also receive care instructions and will need to instil drops into the operated eye to aid with healing and prevent infection.

Your vision should improve after the first week and most people are able to resume activities such as driving after a few days. Bearing in mind, we are all different and some may take more time to heal. It is normal to experience a scratchy sensation for a few days, but if there is an increase in pain, redness, or reduced vision, you must contact your provider immediately.

Different types of lens implants

In young people, a tiny muscle controls the flexible lens and causes it to change shape. The lens changing shape allows us to see objects at different distances clearly, particularly up close. As we age, our lens becomes less flexible and stops changing shape, so we lose this ability to focus up close.  We therefore require glasses to enable us to read, a process called presbyopia. In most cases, it is likely you will need glasses to read fine print after the cataract extraction.

An intraocular lens implant (IOL) made from a crystal clear synthetic material is chosen after your biometry measurement and several factors are taken into consideration when choosing the best lens type for you, this includes your lifestyle and visual requirements.

Monofocal IOLs

The most common IOL type used with cataract surgery is called the monofocal IOL. As the name suggests, monofocal IOL’s have one focusing distance. It can be set for close work, an Intermediate range or for distance vision- depending on your visual requirements. Most people choose to have monofocal IOLs which provide clear distance vision, thus enabling them to drive, watch television or see people in the distance clearly.  With this choice, it is likely that reading glasses will be required to view things up close.

Toric IOLs

Astigmatism is a common optical finding and created when the eye’s focusing power differs in different directions. Simplistically, it is blurred vision created as a result of the shape of the eye.  Astigmatism requires a Toric IOL implant if you would like to obtain improved clarity in vision without glasses.

Multifocal IOLs

A Multifocal IOL is a premium IOL providing both distance and near focus at the same time, therefore reducing the likelihood of needing glasses, although reading glasses for fine print may still be required. Multifocal IOL’s require an adaption period and are not a suitable choice for some, as optical side effects (aberrations, like halos and glare) can be troublesome for some people. It is also not a choice of IOL for people with certain eye conditions such as macular degeneration and glaucoma.


Monovision is a technique which has been used for many years in contact lens wear. It allows the one eye to see in the distance clearly and the other eye is focused for objects at near. Depth perception is affected with this technique and thus it is recommended you trial monovision with contact lenses prior to surgery, to ensure you are comfortable with the idea.

Risks associated with cataract surgery

While cataract surgery is the most commonly performed ocular procedure, it is not risk free. Minor changes in your vision can occur days or even months after the procedure. As mentioned previously, there is still a likelihood of needing glasses to obtain the sharpest vision for different tasks. Occasionally a film develops on the bag or capsule holding the lens implant in place, causing your vision to become mildly blurry. A simple in-office procedure called a “Yag” laser treatment can correct this. Another risk of surgery occurs with the capsule or bag holding the lens in place tears during the procedure. If this occurs, the surgeon will implant an alternative lens to ensure the lens remains safely in position.                

Other more serious risks of surgery include:
  • The possibility that cataract pieces could be left behind after surgery
  • Lens implants slipping out of place
  • Retina detachment
  • Serious infection

Some problems may require additional surgery and rarely, permanent vision loss or blindness may result

In most cases however, the result is successful and excellent.

If you have existing ocular conditions or diseases affecting your eyes such as macular degeneration, glaucoma or diabetes, cataract surgery alone may not restore your vision fully. Prior to undergoing surgery, you will undergo a comprehensive examination by your opthalmologist, which is an opportunity to discuss your options and raise any concerns that you may have.

The good news is that in most cases, cataract surgery offers a fast, painless way to improve your quality of life!