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Five frequently asked questions

about Cataract

Cataract is the leading cause of blindness globally, accounting for 35% of the world’s blindness. 

Below are five frequently asked questions about cataract.
 
COVER PHOTO: Mary Tram (2018)


In a hurry?

Click on the link below to go directly to the question you want answered:

  1. What is cataract?
  2. What causes cataract?
  3. What are the symptoms of cataract?
  4. What are the types of cataract?
  5. Can cataract be cured?



1. What is cataract?

Cataract is the clouding of the lens in the eye that causes vision to diminish over time, and it can affect one or both eyes. In its early stages, cataract may not cause any vision problems with the eye appearing normal to an untrained person. 
 


2. What causes cataract?

While cataract is commonly associated with ageing, not everyone with cataract is old. Some children are born with congenital cataract and, in these cases, early detection and treatment are critical to prevent permanent damage. There are several other causes of cataract, like an injury to the eye, diseases like diabetes, eye inflammation conditions, or it can also be drug induced (mostly steroids). 
 


3. What are the symptoms of cataract?

Once cataract starts to advance, symptoms can include blurry vision; sensitivity to glare; colours appearing dull or faded; double vision; distortion of images; or reading difficulties.
 
The normally clear (black) pupillary area of the eye becomes grey, as a milky cloudiness of the lens progresses until the cataract is mature. In the advanced stage, the pupil appears white.

Once a cataract matures it severely impacts a person’s vision, allowing them to only distinguish between light and dark. 
 
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Three year old Faith with congenital cataracts in both eyes. After having her cataracts removed and intraocular lenses inserted, Faith had her sight restored.
Photographer: Michael Amendolia (2015)
 


4. What are the types of cataract?

Below are some of the most common types of cataract. If left untreated, they can all lead to blindness.

 

Nuclear Cataract

Nuclear cataract affects the center of the lens. In the early stage, sight can improve (known as ‘second sight’) but this is temporary. As it progresses, a dense yellow cloudiness forms that can turn brown. And it becomes difficult to distinguish between colors and small details, while vision gradually decreases.

 

Cortical Cataract

Cortical cataract affects the edges of the lens. In the early stage, wedge-like white streaks or opacities on the outer edge of the lens form, which gradually spread towards the center, making it gradually very difficult to see.

 

Posterior Subcapsular Cataract

Posterior subcapsular cataract affects the back of the lens, right in the path of light entering the eye. This cataract is the fastest to progress, and causes light sensitivity, making it difficult to see in bright light. It can also make reading difficult. It makes driving at night very difficult due to the scattering of incoming light.

 

Congenital Cataract

Congenital cataract is present at birth, and early diagnosis and treatment is the best way to manage this condition. The child’s pupil will appear white, and there is absence or decrease of red reflex which is seen clearly in a normal eye. This type of cataract may result from heredity factors, drug reactions, or from intrauterine trauma or infections. Surgery should be performed as early as possible to correct the eye. 
 


5. Can cataract be cured?

Cataract can be treated with a straightforward surgery. The surgery is performed by an ophthalmologist, and involves removing the cloudy lens tissue, and replacing the natural lens with an artificial implant called an intraocular lens (IOL).
 
The power of the implant is calculated individually for each eye, so the image for distance is brought to focus on the retina, and after surgery the person is usually able to see clearly within a few hours. Medication and care are required for a few weeks until the eye is completely healed.
 
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Professor Fred Hollows holding an IOL
Photographer: George Fetting

 

Learn more:

Discover more about the world's leading cause of blindness - cataract.


DISCLAIMER: 

The content on this page is not intended to be medical advice. For specific medical advice, please contact your health professional.