Cataract: why the lens clouds, and what surgery can do
Not only a disease of old age — and the lens that replaces it is now a choice in its own right.
Inside the eye, behind the iris, sits a clear lens. When it loses its transparency and begins to block vision like a drawn curtain, that is a cataract.
It is commonly thought of as an old person’s condition, and age is indeed the usual cause. But babies can be born with cataract, and it can develop far earlier in life after steroid use, in diabetes, or following an injury.
What happens inside the lens
With age the lens grows heavier and thicker, and its nucleus becomes compressed and hard. The proteins it is made of — the crystallins — undergo chemical change, and as they do the lens loses its clarity.
This is a gradual process, which is why the symptoms are gradual too: colours become duller, glare around headlights and sunlight increases, and the spectacle prescription drifts.
The operation itself
In phacoemulsification the clouded lens is broken up by ultrasound through a small incision and removed, and an artificial intraocular lens is placed in its position. The eye’s own capsule is kept and holds the new lens.
In femtosecond-assisted surgery the 3.2 mm incision and the round opening in the capsule are made with the laser instead of a blade; the lens is then broken up and removed in the same way.
The lens you receive matters as much as the surgery
Cataract surgery has become, in practice, refractive surgery. A monofocal lens gives one clear distance, usually far, with glasses for reading. A trifocal — or “smart” — lens is designed to provide distance, intermediate and near focus, and for many patients can reduce the need for glasses.
Trifocal lenses are not right for every eye. The state of the cornea and the retina, previous eye surgery, and how the patient actually uses their eyes all bear on the decision. This is a conversation to have before the operation, not after it.
What has changed in recent years
Phacoemulsification itself keeps improving: the operation is now performed without an anaesthetic injection, through a smaller incision and without stitches, and the lenses used include multifocal designs and lenses with ultraviolet filters.
Expectations have risen accordingly. A generation ago a successful cataract operation meant clear vision with glasses; today the question is usually whether glasses will be needed at all.
Have your eyes assessed
Send your prescription history, previous eye reports and any corneal imaging for an individual assessment — in person in İstanbul or over video.
This article is for general information only and does not replace a medical examination or personalised medical advice.