A cataract is a painless cloudiness of the lens within your eye which causes blurred vision. They can develop in one or both eyes.

Over time, cataracts become worse and start to affect your vision and your ability to see well enough to drive. Eventually surgery will be needed to remove and replace the affected lens with an artificial one (called an intra ocular implant,) to restore your sight Cataracts may affect your sight in the following ways:

• You may find it increasingly 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
   
  In the UK, most people who are aged 65 or older have some degree of visual impairment caused by cataracts. Men and women are equally affected.