A cataract is a common eye condition where the lens of the eye gradually opacifies i.e. becomes cloudy. This cloudiness makes it more difficult for light to reach the back of the eye (retina), thus causing reduced/blurred vision. Cataracts are the leading cause of curable blindness worldwide.

Epidemiology

• Cataracts are more common in women than in men
• The incidence of cataracts increases with age. One study found that 30% of individuals aged 65 and over had a visually-impairing cataract in either one or both eyes

Causes

• Normal ageing process: most common cause

Other possible causes

• Smoking
• Increased alcohol consumption
• Trauma
• Diabetes mellitus
• Long-term corticosteroids
• Radiation exposure
• Myotonic dystrophy
• Metabolic disorders: hypocalcaemia

Patients typically present with a gradual onset of:

• Reduced vision
• Faded colour vision: making it more difficult to distinguish different colours
• Glare: lights appear brighter than usual
• Halos around lights