Demystifying cataract surgery

The human lens is an extraordinary structure. It is transparent and able to change focus like a zoom lens on a camera. It allows you to focus on both near and distant objects, until you reach 50 years of age. At that age, the lens starts to undergo structural changes that decrease your ability to focus on near tasks, meaning you’ll need reading glasses.

The lens is said to have a cataract when it starts to become less transparent and more opaque.

Most cataracts occur as part of our ageing process. Some may have a specific cause such as diabetes, injury or steroid use.

Cataracts can cause one to lose clarity in their vision, become short-sighted, have a change in colour perception or have increased sensitivity to glare.

The replacement of the human lens with the intraocular lens (IOL) has proven to be perhaps the most successful and life-changing of all surgical procedures undertaken.

Treatment involves removing the cloudy, cataract-affected lens from your eye and replacing it with a clear, artificial lens. Prior to you having the operation, your doctor will discuss the various lens options available to you. Many of these artificial lenses can even correct some astigmatism, which up until now only glasses could correct.

The most commonly used IOLs are called monofocal lenses. These give patients good clear vision, but only at a predetermined distance. You may choose to have your eyes focused to be able to read clearly and then use glasses for distance vision. Other people prefer to see distant objects better without glasses and to use their glasses for reading. A few people may like one eye focused to see distant images and the other focused to see computers, which makes them less reliant on glasses.

Multifocal lenses are a newer, exciting option that can be chosen by people who do not have a high degree of astigmatism or very dry eyes. These allow a person to have functional vision with much less reliance on glasses in most circumstances. Multifocal lenses work by focusing light from near, intermediate and distant objects on the back of the eye at the same time. People usually choose to have a multifocal lens implanted into both eyes, a few days or weeks apart. They offer a good compromise between clear vision and not needing glasses most of the time, but they are not ideal for everyone.

Cataract surgery takes about thirty minutes and is performed in a day surgery or a hospital. An anaesthetist will be available to ensure that you are relaxed during the operation and are not anxious or uncomfortable. The eye is anaesthetised so you will not feel any pain. A small incision is made in the cornea (at the front of the eye). A circular hole is then made in the front of the lens and the cataract is removed using a technique called phacoemulsification. This involves using ultrasound waves to dissolve the cataract and remove it from the eye. The artificial lens is then inserted into the same place where the cataract was removed from. The outer membrane of your natural lens forms a bag-like structure and this stops the artificial lens from moving within the eye.

Some surgeons offer laser cataract surgery, where the first steps of the operation are performed by a laser. These steps are performed more accurately than can be performed manually, but the final vision the person enjoys afterwards is the same regardless of how the operation was performed. The laser is offered as many surgeons believe that it is safer and has a reduced chance of serious complications.