Cataract

A cataract is a clouding of the lens inside the eye, causing gradually blurred vision. It is one of the leading causes of poor vision and preventable blindness in Tanzania, particularly among older adults, and is treatable with surgery.

• Gradually blurred or cloudy vision
• Increased sensitivity to glare, especially bright light or oncoming headlights
• Colours appearing faded or yellowed
• Difficulty seeing well at night
• Frequent changes in eyeglass prescription
• In advanced cataract, a visibly white or cloudy pupil

• Age-related changes in the eye's lens are the most common cause.
• Risk is increased by prolonged exposure to sunlight (ultraviolet light), diabetes, smoking, long-term steroid use, and previous eye injury or inflammation.
• Some cataracts are present at birth (congenital) or occur in infancy.

• Diagnosed through an eye examination, where a health worker or eye specialist observes clouding of the lens using a torch or specialised equipment.
• Visual acuity testing documents the degree of vision loss.
• Assessment for other eye conditions is important, as cataract can coexist with other causes of visual impairment, particularly in older adults.

Cataract surgery — removal of the clouded lens and replacement with an artificial intraocular lens — is the only effective treatment and is a routine, generally safe, and highly successful procedure performed at hospital level or through outreach eye camps.

There is no effective medicine or eye drop treatment to reverse or slow cataract once it has formed.

Surgery is generally recommended once the cataract significantly affects a person's daily activities or independence, and is typically done as day surgery.

Children with congenital cataract require prompt referral for assessment, as early surgery is important to prevent permanent visual impairment (amblyopia).

• Protect the eyes from excessive ultraviolet sunlight exposure, for example with sunglasses or a wide-brimmed hat.
• Manage diabetes well, as poor control can contribute to earlier cataract development.
• Avoid smoking.
• Attend regular eye check-ups, particularly from middle age onward, to detect cataract and other eye conditions early.