What is a Cataract?

A cataract is a clouding of the eye’s natural crystalline lens. The clouding of the lens obscures and scatters light that normally focuses sharply on the back of the eye, causing reduction of vision. A cataract usually occurs as a natural consequence of ageing but it can also occur earlier in life (congenital cataract), be caused by an injury (traumatic cataract), some medications (e.g. steroids) or medical conditions (e.g. diabetes).

Cataracts that occur as a natural part of ageing typically affects both eyes. The onset of symptoms is often insidious, but can sometimes occur fairly rapidly over a few months.

What are the symptoms of a cataract?

  • Cloudy, hazy or foggy vision
  • Worsening distance vision
  • Difficulty reading
  • Difficulty driving at night
  • Glares and haloes around lights (especially at night)
  • Colours appearing duller or less bright
  • Difficulty discerning contrast in colour
  • Becoming more short-sighted and needing more frequent changes in your glasses prescription


Cataract surgery is the only treatment for cataracts. Surgery involves removing the cloudy lens and replacing it with a clear artificial lens implant that allows light to focus sharply again in the eye, restoring clear vision.

How do I know if I need cataract surgery?

The decision of when to proceed with cataract surgery depends on how much the cataract is impairing your vision and how it interferes with your daily life. If you feel that your vision is affecting your ability to perform your normal daily activities, it may be time for cataract surgery. You may also make this decision in consultation with your ophthalmologist.

What does cataract surgery involve?

Cataract surgery is usually performed as a day procedure under local anaesthetic. Surgery takes 20 minutes and one eye is done at a time. Your doctor’s anaesthetist will give you some medication to make you drowsy and relaxed. Drops will be used to numb your eye for the procedure. You will not be able to drive after your surgery; therefore it is important that you arrange transport home on the day of the surgery and to have someone stay overnight with you.

Surgery involves removing the cataract through a small incision and replacing it with a clear lens implant. The incision is so small that it does not even require stitches. The lens implant stays in place throughout your life and does not require replacement.

Will I have to wear glasses after cataract surgery?

In most cases the artificial lens implant is chosen to give good distance vision. Reading glasses are usually needed for near vision and will be prescribed by your optometrist about 4-6 weeks after surgery.

Some newer lens implants are able to give you both clear distance and near vision, reducing your dependence on glasses. Discuss this with your surgeon if you would like to explore these options.