A cataract is a clouding or opacity of part of your eye called the lens. Vision becomes blurred because the cataract is like a frosted glass, interfering with your sight. Cataracts tend to develop slowly over time causing a gradual loss of clarity of vision. It is not a layer of skin that grows over your eye, despite what you may have heard.
If your doctor or optometrist/optician has told you that you have a cataract, don't be alarmed. Most people over 60 have have a degree of cataract and the vast majority can be treated successfully. Early cataracts may not affect your sight and do not need treatment.
The function of the lens
The lens is a clear tissue found behind the iris, the coloured part of the eye. The lens helps to focus light on the retina at the back of the eye to form an image just like a lens in a camera. To help produce a sharp image, the lens must be clear.
The effect of cataracts
Blurry sight :this is very common. You may notice that your sight has become blurred or misty, or that your glasses seem dirty or appear scratched.
Dazzled by light: You may be dazzled by lights, such as car headlamps, and sunlight.
Change of colour vision: Your colour vision may become washed out or faded.
These eye problems may be a sign of other eye conditions. If you suffer from any of these symptoms, please see your optometrist/optician. Regular eye tests with your optometrist/optician can catch an eye condition in the very early stages.
Causes of cataract
Cataracts can form at any age. The most common type of cataract are age-related cataract. These develop as people get older. In younger people cataracts can result from conditions such as diabetes, certain medications and other longstanding eye problems.
Cataracts can also be present at birth. These are called congenital cataracts.
Although researchers are learning more about cataracts, no one knows for sure what causes them. There may be several causes and some studies have linked smoking, excessive exposure to sunlight and poor diet with cataract development. Sometimes cataracts are caused by other health problems such as diabetes.
The only effective treatment for cataract is an operation to remove the cloudy lens.
Timing a cataract operation
In the past, eye specialists often waited until the cataract became "ripe" and your vision was very poor before suggesting you had the cataract removed.
Nowadays, with modern surgery the operation is usually done as soon as your eyesight interferes with your daily life. This includes having any difficulties with looking after yourself or others, cooking, driving, getting out and about, being able to read, work or do the things you enjoy.
If you are a driver you must reach the visual standard required by the Drivers and Vehicle Licensing Authority, and it may be necessary to have the cataract removed in order to keep your license.
Before the operation
Before the operation, you and your eye will be carefully checked to decide the details of the operation. This may require a separate visit before your surgery. This is called a pre-operative assessment.
Modern cataract surgery is performed by a technique called phaco-emulsification. The cataract is broken up using ultr-sound energy and removed from the eye
The operation is performed with the aid of a microscope, through a small opening in the eye. This opening is so small that stitches are not necessary.
The operation often takes about 10 -15 minutes, although it can last longer.
During the operation the lens with the cataract is removed and replaced with a clear plastic lens, so that the eye can see clearly after the operation. This plastic lens is called an intraocular lens implant and remains permanently inside your eye. There is no risk of your eye rejecting the new lens.
A clear shield will probably be put over your eye to protect it from accidental rubbing and bumping after the operation.
The operation cannot be performed with laser, although laser treatment is sometimes needed afterwards if the lens casing (the capsule) becomes cloudy.
We want to reassure you that your eye is not taken out of its socket during surgery.
Almost everyone has a local anaesthetic. With a local anaesthetic, you will be wide awake but feel nothing in your eye. I use only local anaesthetic drops with no needles in or around the eye. You may vaguely see some movement but no details of the operation.
If, however, you do have a general anaesthetic you will be completely unconscious, and it will be like sleeping through the operation.
After the operation
Most people notice an instant improvement in sight, although complete healing may take several months. You may still need glasses, especially for reading, because the new intraocular lens implant is normally set up for distance vision and not close-to vision.
If you were wearing glasses for distance vision (short-sightedness) before surgery your glasses prescription will probably change following surgery. This is because the new intraocular lens can be set up to correct short-sightedness.
You will be given eye drops to use for 4 weeks after your operation. It is a good idea to have some help at home, especially if you find it difficult to put your eye drops in.
Most people will have the operation and go home on the same day, and will probably be able to carry on with normal daily activities - but do think about the following:
avoid rubbing your eye; discuss wearing an eye shield with hospital staff if you are a restless sleeper
don't do any very heavy lifting, and avoid strenuous exercise and swimming
take care if it is windy, in case anything blows in your eye, although you don't need to stay indoors
take care washing your hair; avoid getting soapy water in your eye(s)
Cataract surgery is one of the most successful operations. Fewer than one per cent of patients have serious, unforeseen complications
One of the most common and easily correctable complications is a thickening of the lens casing - the part of the eye that holds the lens in place. As mentioned earlier, this can easily be corrected with laser treatment .
Bespoke Surgery for spectacle independence
Astigmatism is a condition where the cornea (the clear window at the front of the eye) isn't perfectly round, but slightly oval in shape. This distorts the vision but is usually corrected with glasses. This optical defect can be corrected by the use of toric lens implants to give more spectacle independence. Toric lenses can be multifocal (see below)l or single focus (distance vision)
Multifocal lens implants.
Whilst many people are happy to have good distance vision and wear glasses for reading some will desire to be rid of glasses altogether. With modern surgical techniques and lens implants it is possible to give good distance and reading vision using multi-focal lens implants. There is never 100% guarantee of complete spectacle independence but the majority of people can do all their daily tasks such as driving, shopping and reading with out glasses.
Not all patients will be suitable for this type of lens implant which can be discussed prior to surgery.