A cataract develops when the crystalline lens — the eye's natural lens, whose job is to focus light sharply on the retina — loses its transparency, mainly as a result of ageing.
As the lens clouds over, light passes through it less easily, and both vision and quality of life deteriorate.
What are they?
The condition we call a cataract is the clouding of the crystalline lens. Normally the lens is transparent: light passes through it and is focused on the retina with the help of the cornea, producing a sharp image. If the lens becomes opaque, usually with age, light no longer reaches the inside of the eye properly, giving a blurred image that can eventually lead to complete blindness.
What causes cataracts
The most common type of cataract is age-related. It affects 50 % of people aged 65 to 74, and 70 % of those over 75. Less common causes include medicines such as corticosteroids, eye injuries or perforations, conditions such as diabetes mellitus, prolonged unprotected exposure to sunlight, and previous eye surgery.
Symptoms
The commonest sign that suggests a cataract is a drop in vision. Less frequent symptoms include colours looking duller, poor night vision, and suddenly being able to read without the glasses you previously needed.
Blurred vision, colours losing their intensity or taking on a yellowish cast, poor night vision, frequent glare, needing brighter light to read, or double vision are all symptoms that should raise the suspicion of a cataract and prompt a visit to the ophthalmologist for a diagnosis.
When should you have surgery?
It is a mistake to wait until you are nearly blind, or for the cataract to «ripen», before having surgery: you will spend a long time seeing poorly, and the operation becomes harder and carries a greater risk of complications.
Surgery should therefore be considered once the cataract causes enough loss of vision to interfere with everyday activities. The decision is yours: only you can decide when it is time to open your eyes to a clear, bright world.
Treatment
Phacoemulsification is the most advanced way of treating cataracts definitively. It allows a very straightforward day-case operation, quick — it takes only eight minutes — and under topical (drop) anaesthesia, which avoids many complications: patients can, for example, carry on taking their usual medication. No sutures are needed and recovery is very fast.
How is phacoemulsification performed?
Ultrasound is used to dissolve the lens, which is then aspirated. Through a small incision we insert an intraocular lens that takes over the role of the natural lens. This lens lasts a lifetime, does not lose its transparency and causes no rejection.
Once the operation is over, patients walk out on their own, with the eye uncovered and with very rapid visual recovery.
Cataracts and ageing eyesight
After cataract surgery, patients usually need reading, bifocal or varifocal glasses to read and focus on close objects. But thanks to the multifocal intraocular lens we can not only remove the cataract but also give patients a full range of vision — from reading a book to watching television — without glasses, permanently.
What a cataract looks like from the inside
Move the slider to see how the scene changes as the lens loses transparency and turns yellow.
