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.
Photographs of different
types of cataract
Cataracts can occur as a result of diseases or
injury to the eye, but most commonly occur as a result of ageing.
Occasionally conditions such as diabetes lead to the early development of
The treatment of cataract is by surgery. Cataract
surgery is normally performed under local anaesthetic (although some
patients prefer general anaesthetic).
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 require stitches).
A folding acrylic lens is inserted into the eye to
replace the cloudy lens. 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
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
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 operations.
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