The human eye contains a lens that focuses light within the eye. When
this lens becomes cloudy it is called a cataract.
Cataract can lead to blurring and mistiness of vision and also to ‘glare’
which is the worsening of vision in bright light. Particularly troublesome
examples of glare include dazzle caused by on-coming headlights and
worsening of vision in bright sunshine.
Cataracts can occur as a result of diseases or injury to the eye, but most
commonly occur as a result of ageing. Conditions such as diabetes can lead
to the early development of cataracts.
Photographs of different
types of cataract
The treatment of cataract is by surgery. Cataract surgery is normally
performed under local anaesthetic (although some patients prefer general
During the operation the cataract is broken down into small pieces using
high frequency ultrasound (called phaco-emulsification). The pieces are then
removed via a tiny incision that is self-sealing (so small it does not
A folding acrylic lens is inserted into the eye to replace the cloudy
Surgery usually takes about 20 minutes and the patient is
free to leave within 30 minutes of the operation.
By adjusting the strength of the implanted lens, it is often possible to
correct long or short sightedness and reduce the need for strong glasses.
Most cataract operations will result in a return to normal
vision as long as the eye does not have other eye disease such
as macular degeneration.
The correct time for surgery depends very much on how much nuisance the
cataract is causing the patient. In addition, some people such as drivers or
pilots require a very good level of vision, and may wish to undergo surgery
sooner in order to carry on these activities. The old fashioned concept of
the cataract having to ‘ripen’ is no longer the case.
Complications of cataract surgery are fortunately uncommon. The most
serious complication is infection which can blind the eye, however this
complication is rare, occurring only in approximately 1 in 1,000 cataract
Other complications that occasionally occur include dislocation of part
of the cataract into the back of the eye, or problems with the retina such
as swelling of the retina (macular oedema), retinal detachment or bleeding,
all of which require further surgery to correct. As a vitreoretinal surgeon,
I specialize in the surgery to correct these complications.