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Cataract and cataract surgery: General information

What is a cataract



The word cataract is an ancient term which is used in medicine to describe a cloudy lens. The lens is an important optical part of the eye, and is positioned right behind the pupil, inside the eyeball. Like the lens in a camera or in spectacles, the lens in the eye focuses the image we see. To do that, it needs to be transparent.


The lens may lose its clarity and become cloudy or opaque, and when it does, we refer to the problem with the often misunderstood term “cataract”. Many patients think, incorrectly, that a cataract is “a growth” which has to be peeled from surface of the eye. It is not. It is simply a cloudy lens. In fact, it would be more appropriate to use an adjective than a noun to describe this problem, as cataract is a property of the lens (becoming cloudy) rather than an object which has "formed" in the eye, as this confusing term suggests.


Clouding of the lens occurs naturally with ageing, usually in people over 50 years old. However, cataract may occur at younger ages in people with certain diseases (e.g. diabetes), people who use certain medications (most commonly cortisone derivatives) or who have other longstanding eye problems (uveitis, pervious injury to the eye, previous surgery on the eye, especially vitrectomy). They also occur earlier in heavy smokers.


Cataracts may initially cause no symptoms, but gradually cause blurring of vision, glare when driving at night or in strong sunlight, difficulty reading or recognising detail in general. In some patients, the first symptom is a progressive change in their required spectacle perscription.


In most cases, cataracts can be diagnosed easily by observing the lens through a dilated pupil using a slit lamp (the ophthalmologist’s examination microscope).





What is cataract surgery?

Cataract surgery is one of the most common surgical procedures done worldwide. Modern cataract surgery is quick, highly successful and often has dramatic effects on the patient’s vision. While any surgical procedure carries some risks, cataract surgery has a very low complication rate.


The operation involves removal of the natural, cloudy lens from the eye and implanting a prosthetic, artificial lens in its place.


In most patients, this is done under local anaesthetic. Typically, the actual operation takes 10-15 minutes from start to end. The patient typically spends a total of 2-3 hours in the hospital, for admission procedures, recovery time, etc.


The most common technique used to remove the lens is with an ultrasound probe which breaks the lens into tiny fragments that are then removed from the eye by vacuum. A special synthetic lens is then introduced into the eye and stays there for life. That lens is individually selected according to computerised calculations using the patient’s eye size and optical properties.


Although the operation is primarily done to remove the cloudy lens, it serves as an opportunity to also correct “refractive errors” such as short sightedness (myopia), far sightedness (hyperopia) and astigmatism. This is done according to the patient’s needs and wishes, as discussed before the operation. Therefore, patients are often much less dependent on glasses after cataract surgery.


When is cataract surgery required?

It depends. There are many factors affecting the decision about timing of surgery. As a rule, if the patient has disturbing visual symptoms related to clouding of their lens, and if there is reason to believe that all the other systems in the eye (retina, optic nerve) work well, cataract surgery is likely to be helpful.


There is an old misconception that cataracts have to be “ready to be removed” or “ripe”. This dates back to the days when cataract surgery was difficult and risky, and was taken as a last resort, when the patient was close to blindness from his/her cataract. These days, the operation may be done as soon as required for the patient’s visual needs. A visually frustrated truck driver will therefore be operated earlier than a person who doesn’t drive and has few or no visual symptoms.


Cataract surgery is rarely an urgently needed procedure. Most cataracts evolve slowly over years and there is a very long “window of opportunity” to remove them successfully.


However, very advanced cataracts may become difficult to remove surgically and even cause other eye problems (glaucoma, uveitis). When this is the case, the cloudy lens has to be removed quickly. 

What should I expect after cataract surgery?

In most cases there is rapid visual recovery in the operated eye, with continuous improvement during the first days to weeks after surgery. Often there is some discomfort, with foreign body sensation, light sensitivity or tearing in the first few weeks, although in some patients, mild ocular discomfort persists for several months.


The patient’s previous glasses have to be updated after surgery. Some patients only require reading glasses after cataract surgery, others need glasses for distance and near (multifocals) and some patients may be free of glasses, if using “Monovision” technique or if the surgeon implants multifocal lenses during surgery. Click here for more information on intraocular lenses.


Where will I be operated?
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