A cataract is a clouding of the normally clear lens inside the eye. It develops slowly and makes vision blurry, dim or faded, like looking through a frosted window. Cataracts are the leading cause of blindness worldwide, including in Nigeria. The good news is that cataract surgery is safe, quick and highly effective at restoring sight.
Key facts
- Most cataracts are caused by ageing and develop after age 50.
- Diabetes, smoking, sunlight and steroid use increase the risk.
- Cataracts are not caused by using the eyes too much, and they do not spread from one eye to the other.
- Glasses may help early on, but surgery is the only treatment that removes a cataract.
- Cataract surgery is one of the most successful operations in medicine.
Causes and risk factors
- Ageing, the most common cause
- Diabetes
- Smoking and heavy alcohol use
- Long-term exposure to strong sunlight (ultraviolet light)
- Long-term use of steroid tablets or eye drops
- Eye injury or previous eye surgery
- Family history
- Congenital cataracts, present at birth, sometimes due to infections in pregnancy such as rubella
Symptoms
- Cloudy, blurry or misty vision
- Colours looking faded or yellowish
- Difficulty seeing in dim light or at night
- Glare and halos around lights, including car headlights
- Frequent changes in glasses prescription
- Double vision in one eye
- A white or grey appearance in the pupil in advanced cataracts
Cataracts are usually painless. A painful, red eye with blurred vision needs urgent attention because it may be a different condition, such as acute glaucoma.
Diagnosis
An eye health worker or ophthalmologist will check your vision with a letter chart and examine the lens using a slit lamp microscope, often after putting drops in to widen the pupil. They will also check for other eye conditions, such as glaucoma and diabetic eye disease, that can affect vision.
Treatment
Early cataracts
Stronger glasses, brighter lighting and anti-glare sunglasses can help for a while.
Cataract surgery
Surgery is recommended when cataracts affect daily life, such as reading, working, recognising faces or moving around safely. During surgery:
- The eye is numbed with drops or a local anaesthetic injection. You are usually awake.
- The surgeon removes the cloudy lens through a small cut and replaces it with a clear artificial lens (intraocular lens).
- The operation usually takes 15 to 30 minutes, and most people go home the same day.
Common techniques include phacoemulsification, which uses ultrasound to break up the lens through a tiny incision, and manual small-incision cataract surgery, widely used in Nigeria and other countries with excellent results and at lower cost.
After surgery
- Use the prescribed eye drops for several weeks to prevent infection and inflammation.
- Wear an eye shield at night for the first week.
- Avoid rubbing the eye, swimming and heavy lifting for a few weeks.
- Attend follow-up appointments. You may need new glasses after a few weeks.
Sometimes the thin membrane behind the new lens becomes cloudy months or years later. This is easily treated with a quick laser procedure.
Avoid harmful traditional treatments
“Couching”, in which a traditional practitioner pushes the lens back into the eye, still occurs in some communities. It often leads to infection, severe complications and permanent blindness. Eye drops or herbal remedies cannot dissolve cataracts. Always seek care from a qualified eye health worker.
Prevention
- Wear sunglasses and a wide-brimmed hat in bright sunlight.
- Stop smoking.
- Control diabetes well.
- Eat plenty of fruit and vegetables.
- Use steroids only as prescribed.
- Protect your eyes from injury at work and during sports.
- Have regular eye checks, especially after age 40 or if you have diabetes.
When to see a doctor
See an eye health worker if your vision is becoming cloudy, dim or glary, or if you notice a white patch in your own or your child’s pupil. Seek urgent care for sudden vision loss, a painful red eye, flashes of light or a curtain over your vision, or pain, increasing redness or worsening vision after cataract surgery.
Frequently asked questions
Can cataracts come back after surgery?
No. The artificial lens does not develop a cataract, although the membrane behind it can cloud and is easily treated with laser.
Is cataract surgery painful?
Most people feel little or no pain because the eye is numbed. Some mild discomfort afterwards is normal.
Related guides
Sources
- World Health Organization: Blindness and vision impairment fact sheet
- NHS: Cataracts in adults
- National Eye Institute (NIH): Cataracts
