A cataract is a cloudy patch in the lens of the eye which can cause vision to become misty or blurred. It is the most common cause of vision loss in people over the age of 40, and can occur in one or both eyes. Cataracts can be treated and removed to restore eyesight and do not usually result in permanent or long term loss of sight.
Type of cataracts
There are three main types of cataracts:
- The subcapsular cataract: This is a cataract that forms at the back of the lens, and people who are taking steroids or suffering from diabetes are most at risk of this type.
- The nuclear cataract: This type of cataract forms deep in the central area of the lens and is most commonly associated with ageing.
- The cortical cataract: This type occurs in the lens cortex, which is the portion of the lens that surrounds the central nucleus. It is characterised by white, wedge shaped opaque areas which start at the edges and work their way into the centre like spokes on a wheel.
Why do we get cataracts?
Cataracts are most commonly associated with growing older and many otherwise healthy people will develop a cataract at some point in their lives. In addition to the natural ageing process, there are some other reasons that people might experience a cataract. These can include:
- Suffering with diabetes
- Trauma to the eye, such as a blow or perforation
- Taking particular medications such as steroids and statins
- After eye surgery for other conditions
- Having a family history of cataracts
As well as these mainly unavoidable reasons, there are a number of other factors that may be involved in the formation of cataracts, some of which can be avoided. These include:
- Excessive alcohol consumption
- Excessive exposure to ultraviolet light, such as sunlight
- Poor diet with few antioxidants
Research into these other influencing factors is still ongoing, but early indications are that people who exhibit one or more of these factors are more at risk of developing a cataract.
Symptoms to look out for
The development of cataracts is very slow and steady, and for many people the changes are hard to notice at first. In the early stages of cataract development, you may feel like your reading glasses are dirty, even though the lenses are clear. Bright lights can affect cataracts a great deal, so you might feel more dazzled by oncoming cars than before. Colours can change too, particularly if you have a cataract in one eye and not the other. Whites may appear more yellowish, and other colours slightly washed out.
As soon as you notice any of these changes, you should make an appointment to see your optometrist. They will be able to test your eyes and see if you have a cataract forming or not. If you don’t see anyone about the cataract, then your sight will continue to get cloudier, until eventually it becomes like trying to see through frosted glass. However, the good news is that even if your cataract gets to a highly developed stage, usually it can still be removed and your sight will return to normal after the treatment.
How cataracts can be treated
Cataracts can be removed at any stage of their development, so as soon as your vision starts to become impaired it is time to think about having surgery. Cataract surgery is very straight forward, involving only a local anaesthetic and taking around 30 – 45 minutes to complete. Most people are able to go home within a few hours after their surgery, and complications following the procedure are very rare.
The process of a cataract operation takes just a few simple steps:
- The patient is given eye drops to dilate the pupil and is given a local anaesthetic, either in the form of eye drops or an injection
- The surgeon makes a tiny incision into the cornea
- Using a specialist tool, the surgeon directs ultrasound waves at the cloudy lens, which break it up for removal
- The lens is removed easily by suction
- A prosthetic lens is implanted into the eye which will last for the rest of the patients life
After surgery, some patients can see much better straight away, although full vision usually takes a few days to come back. The eye may be swollen from the surgery, but is rarely painful.
Prevention of cataracts
Recent studies have shown that a highly nutritious diet, rich in vitamin E (from foods such as sunflower seeds, almonds and spinach) can reduce the risk of cataracts forming. Carotenoids lutein and zeaxanthin which are found in spinach, kale and other green, leafy vegetables are also thought to prevent cataracts from forming, as well as vitamin C and foods containing Omega-3 fatty acids. Other studies have shown that cataract development is more prevalent in meat eaters.