Cataracts are cloudy patches that develop in the clear lens inside your eye, stopping some of the light from reaching the back of the eye, and causing blurred or misty vision. They are very common, in fact, cataracts are the leading cause of blindness in adults worldwide. However, in most cases cataracts can be successfully treated and vision restored.
According to Medibank, more than 700,000 Australians are now affected by cataracts. Medibank clinical director Dr Sue Abhary said about the findings: “It’s well known that the risk of developing cataracts increases as people get older. The good news is that most cataract surgeries are straightforward procedures, and are available within the public health system under Medicare, as well as privately via health insurance, so help is always available to those who need it.
“If you’re going through the public system, it’s worth checking the average waiting period for cataract surgery in your state, as these can differ greatly depending on where you are, and can be disruptive if you’ve lost some vision and are having trouble with day-to-day activities such as driving.”
Cataract warning signs
Cataracts develop slowly and, though problems may at first be unnoticeable, there are some early warning signs that can alert you to this vision problem.
One of the first symptoms you may notice is that your vision is blurred or distorted, much like looking through a cloudy piece of glass. You may also have the sense of seeing double or see ‘halos’ around lights or find that objects have a brown or yellow tinge. Cataracts can affect one eye only or both eyes.
A cataract can make the light from the sun or even a lamp feel too bright or glaring. Or you may notice that when you drive at night the oncoming headlights cause more glare than before. Colours may not appear as bright as they once did and you may have trouble seeing faces or other details clearly.
Cataracts can change your eyes focusing power. If you find your eye glass prescription needs changing frequently, or your vision has changed, see your optometrist.
Cataracts don’t generally cause pain but the symptoms, such as sensitivity to light, may cause discomfort.
When cataracts are advanced, the pupil of the eye may appear grey or white.
Types of cataracts
The symptoms you experience will be directly related to the type of cataract that you have.
Cataracts affecting the centre of the lens (nuclear cataracts). A nuclear cataract may at first cause a temporary improvement in your reading vision. But with time, the lens gradually turns more densely yellow and further clouds your vision.
As the cataract slowly progresses, the lens may even turn brown. Advanced yellowing or browning of the lens can lead to difficulty distinguishing between shades of colour. Nuclear cataracts are usually associated with ageing.
Cataracts that affect the edges of the lens (cortical cataracts). A cortical cataract is characterised by white, wedge-like opacities that start in the periphery of the lens and work their way to the centre in a spoke-like fashion. As it slowly progresses, the streaks extend to the centre and interfere with light passing through the centre of the lens.
Cataracts that affect the back of the lens (posterior subcapsular cataracts). A posterior subcapsular cataract starts as a small, opaque area that usually forms near the back of the lens, right in the path of light. People with diabetes or those taking high doses of steroid medications have a greater risk of developing a subcapsular cataract.
This type of cataract often interferes with your reading vision, reduces your vision in bright light, and causes glare or halos around lights at night. These types of cataracts tend to progress faster than other types do, they also may not cause any symptoms until well developed, after which they can develop much more rapidly.
How cataracts are caused
Cataracts are caused by changes to the lens of your eye, mostly associated with ageing and exposure to ultraviolet light. Cataracts develop when proteins in the lens are damaged and clump together. This reduces the amount of light that can pass through the lens to the retina, which leads to a loss of vision.
As you get older it’s normal that these proteins in the lens of the eye start to break down and clump together. This causes the characteristic cloudiness in the lens that is a cataract.
Exposure to ultraviolet light also increases the risk of cataracts — experts think this happens through oxidative stress — the same process that causes skin damage from the sun.
If you think you have a cataract, book an appointment with an optometrist for an exam to find out for sure.
Have you ever had cataract surgery? Do you have a family history of cataracts? Are you worried about vision problems as you age?