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A cataract is a common eye condition where the lens becomes progressively opaque, resulting in blurred vision. Having a cataract can be compared to a dirty camera lens or a foggy window.


The blurring of one’s vision, due to a cataract, can make it difficult to read print or see clearly in the distance. Some types of cataracts create glare, making the vision worse in bright light. Driving at night may also be difficult.  

Some patients with a cataract notice a change in the appearance of colours, typically a fading or general yellowing. Occasionally a cataract can cause double vision in one eye, meaning with only one eye open, two images are seen.

Cataracts can also change the focusing power of the eye and therefore the strength of glasses is needed. Frequent prescription changes can indicate the development of a cataract.


There are many causes of cataract formation, however, ageing is the most common.

As people grow older, changes to the protein that make up the lens can occur, these changes can lead to the development of cloudy areas. It is unknown how or why ageing causes these changes, however, research suggests that genetic, nutritional and environmental factors contribute.

Cataracts can be hereditary and are occasionally seen in infants and children. Injury to the eye may also cause a cataract, as well as the use of some medications, such as steroids. Medical problems such as diabetes can be associated with cataract formation, most often in younger people. Previous eye surgery and other eye diseases may also cause cataract formation.


A thorough eye examination by an ophthalmologist will determine whether a cataract is present. In the early stages of cataract development a change in glasses may be all that is needed. A complete eye examination will also determine if there are other causes of vision loss, particularly problems involving the retina or optic nerve.

Risk Factors

Research suggests that some factors may increase the risk of age-related cataracts forming, including;

  • diabetes,
  • a family history of cataracts,
  • use of steroid medication over time,
  • lifestyle factors, such as poor diet and smoking,
  • excessive exposure to sunlight over time.


A cataract does not have to be removed just because it is there. Surgery will be considered when a cataract causes enough vision loss to interfere with daily activities, such as; work, driving, reading or watching TV.

It is a misconception that a cataract needs to be “ripe” before it can be removed. Surgery is performed when a person’s visual needs require it. An ophthalmologist can decide when surgery is appropriate.

Surgery is the only effective way to remove a cataract and is usually performed in a hospital’s operating theatre under a local anaesthetic. The cataract is removed using a microscope and miniature instruments. In most cases, an intraocular lens implant is placed in the eye to restore the focusing power of the natural lens. If an intraocular lens is not implanted, cataract glasses or a contact lens will be needed after surgery.

Most patients go home from the hospital on the day of surgery.

If a cataract has developed in both eyes, treatment will not be given to both at the same time. It is common for a cataract to develop quicker in one eye than the other, therefore the more seriously affected eye will be treated first.

There are no known medications or dietary supplements that will prevent or cure a cataract, and it is a common misconception that lasers are used to remove a cataract.

The Lions Eye Institute also conducts an array of Clinical Trials. You can view these on our Clinical Trials page.

Further Information & Support

For further information view our Cataract Brochure . Here you will find information on the; type of implants used, anaesthesia, side effects, recovery, risks and implications.

If you have any questions or concerns about any aspect of cataract care, please discuss these with an ophthalmologist.

What’s Next?

All ophthalmologists at The Lions Eye Institute can assist with cataract advice and treatment.  A current referral from either a GP, or an optometrist, is required for all appointments.

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