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A cataract is a clouding of the normally transparent lens of the eye. Cataracts are one of the leading causes of vision impairment in Australia, so it’s important you know what to look out for.
Most age-related cataracts develop slowly, remaining symptom-free for years or decades. Because your eyes are able to compensate for minor visual disturbances, even a medium-sized cataract may not necessarily cause a noticeable change in your vision. Only after years of growth, when the cataract affects a significant amount of your lens, will the first cataract symptoms become noticeable.
However, in some rare cases or in people at high risk, cataracts may develop quickly (over several months). Therefore, regular eye checks are important for everyone – not just for people who wear glasses or experience symptoms.
While there is no substitute for regular eye checks, the next best thing you can do is be aware of what to look out for.
Blurred vision is often the first sign of a cataract. A cloudy lens is like a layer of frosted glass, which blocks some of the light that would usually pass through to your eye. The cloudy lens also disrupts the light that does manage to pass through, resulting in blurred vision.
Usually, the lens focuses light on the back of your eye (the retina) very precisely. However, the cloudy lens of a cataract scatters some of the light in different directions. The scattered light creates glare and sensitivity to bright lights.
As the cataract forms, the lens hardens and becomes more yellow. This hard, physical barrier blocks light and acts like a yellow filter. Because of this, the vibrancy and brightness of colours does not make it through to the eye. This results in colours that look faded with a yellow tinge.
In the same way that a cloudy lens causes glare sensitivity, it may also result in double vision. The cloudy lens may split incoming light in two, instead of focusing it at a single point. This can produce double vision or a ghost-like image next to objects.
When light scatters, it may also produce a glow (halo) around lights or bright objects.
All vision will appear dim and/or distorted due to the cloudy barrier. Low-light conditions, especially in combination with glare sensitivity, tend to make your already reduced vision much worse.
Note: Visual symptoms may vary from person to person. The images above are for illustration purposes only. The second image shows how objects are seen by a person with severe cataracts.
The severity of symptoms will depend on which type of cataract you have.
There are many different types of cataract, but the 3 most common are nuclear, cortical and posterior subcapsular. Regardless of which type you have, symptoms will generally worsen over time if cataracts are left untreated.
These symptoms can significantly reduce a person’s quality of life and increase the risk of other health problems. In addition to the above symptoms, advanced cataracts can lead to an increased falls risk, social isolation and depression.
To avoid these issues, it’s best to have your vision assessed as soon as you first notice any signs or symptoms of a cataract.
The information on this page is general in nature. All medical and surgical procedures have potential benefits and risks. Consult your ophthalmologist for specific medical advice.
Date last reviewed: 2023-05-19 | Date for next review: 2025-05-19