What is a Cataract?

Cataracts are cloudy patches that develop in the lens of your eye and can cause blurred or misty vision. They are very common. The lens is the transparent structure that sits just behind your pupil (the black dot in the centre of your eye). It allows light to get to the back of your eye (retina). In some people, cataracts develop in the lens as they get older, stopping some of the light from reaching the back of the eye. Over time, the cataracts become worse and start affecting vision. They often develop in both eyes, although each eye may be affected differently. You will usually have blurred, cloudy or misty vision, or you may have small spots or patches where your vision is less clear. Cataracts may also affect your sight in the following ways:
  • you may find it more difficult to see in dim or very bright light
  • the glare from bright lights may be dazzling or uncomfortable to look at
  • colours may look faded or less clear
  • everything may have a yellow or brown tinge
  • you may have double vision
  • you may see a halo (a circle of light) around bright lights, such as car headlights or street lights
  • if you wear glasses, you may find that they become less effective over time
Cataracts are not painful and don’t make your eyes red or irritated. Although rare types of cataracts affect babies and young children (congenital cataracts), the problem is much more common in older people. As well as your age, several other factors may increase your risk of developing cataracts, including:
  • a history of cataracts in your family
  • smoking
  • regularly drinking excessive amounts of alcohol
  • a poor diet lacking in vitamins
  • lifelong exposure of your eyes to sunlight
  • taking corticosteroid medication at a high dose or for a long time
  • previous eye surgery or injury
  • certain health conditions, such as diabetes or long-term uveitis (inflammation of the middle layer of the eye)
If your cataracts are mild, stronger glasses and brighter reading lights may be helpful for some time. However, cataracts get worse over time so it’s likely you will eventually need surgery to remove them. There is a belief that your cataracts need to be “ripe enough” to remove – this is not exactly true. We usually recommend you have your cataracts removed when you are having difficulty seeing an every task and your optician cannot improve your sight with glasses. Cataract surgery involves removing the cloudy lens through a small incision (cut) in your eye and replacing it with a clear plastic one. In most cases, this will be carried out under local anaesthetic (where you are awake, but the eye is numbed) and you can usually go home the same day. After the operation, your plastic lens will be set up for a certain level of vision, so you may need to wear glasses in order to see objects that are either far away or close to you. If you wore glasses previously, your prescription will probably change. However, your optometrist will need to wait until your vision has settled before they can give you a new prescription, this usually takes between 4 and 6 weeks.