A cataract is a common eye condition in which the lens inside the eye loses its transparency. The lens is the part of the eye that helps to focus light on the retina, the light-sensitive layer on which images are formed. In healthy eyes, the lens is clear and allows light to pass through. When the lens is cloudy from a cataract, the images appear blurred, a bit like looking through a dirty window.
What are cataracts?
There are three types of Cataracts
Nuclear cataracts affect the centre of the lens and can make it difficult to distinguish colours
Cortical cataracts affect the outer edge of the lens
Posterior subcapsular cataracts form at the back of the lens. They interfere especially with reading and cause haloes to form around lights. This type of cataract tends to progress faster than the other types1.
What are the symptoms of cataracts?
- Blurred, misty or cloudy vision
- Bright lights may be dazzling or uncomfortable to look at
- Colours may look faded or less clear with a yellow or brown tinge
- You may find it more difficult to see in dim or very bright light
- You may have double vision
- You may see haloes (circles of light) around bright lights, such as car headlights or streetlights
Cataracts usually develop slowly over many years, so you may not notice symptoms at first. They often develop in both eyes, although each eye may be affected differently.
Cataracts are not painful and don’t make your eyes red or irritated. You’ll usually have blurred, cloudy or misty vision, or you may have small spots or patches where your vision is less clear.
Cataract surgery is done under local anaesthetic, so you’ll be awake, but your ophthalmologist will make sure you don’t feel the area around your eye, and you can be sedated if you are particularly anxious. It’s a very common and successful procedure and involves taking out the cloudy lens and replacing it with a clear, artificial one. This artificial lens cannot cloud over in the same way, and so cataracts do not grow back after surgery.
There are two types of cataract surgery: small incision cataract surgery (phacoemulsification) and extracapsular cataract extraction. These surgeries are usually done on an outpatient basis, so you shouldn’t need to stay at the hospital overnight, and it usually takes less than an hour to perform.
Large multi-centre studies have shown there is no increased risk of progression to the advanced (wet) form of AMD in patients who undergo cataract surgery. Moreover, nutrients such as vitamin C, vitamin E, zinc, lutein, and zeaxanthin have been found to substantially reduce the risk of AMD progressing to advanced stages.
Complications from cataract surgeries are rare. In patients with AMD, the clinical approach may simply need to be altered and some special precautions taken. There is usually no need to stop treatment for macular degeneration: anti-VEGF injections for AMD can continue in people who have, or who have not undergone cataract surgery. These are injections that reduce the growth of new blood vessels beneath the macula.