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Patient Information: Cataract Surgery


This leaflet explains to you what a cataract is, what to expect before, during and after your surgery, and lists the potential complications of surgery. Most people do very well after surgery and complications are rare. However, they can occur, and it is important to be aware of what they are before you decide to proceed with your operation.

What is a cataract?

Think of your eye as being like a camera with a lens, which is crystal clear and focuses light on the back of the eye. The picture created is then transmitted to the brain along a nerve called the optic nerve, and this is how you see.

If the lens becomes cloudy in anyway, your vision becomes blurred or you may experience glare or very blurred vision in certain lighting conditions, such as a sunny day or when driving against oncoming headlights at night. Some people with cataracts feel as if they are looking through dirty glasses, they therefore keep cleaning their glasses, which of course makes no difference at all.

How is the cataract removed?

The cataract is removed through a very tiny incision (2.75mm) using a microscope, and a new lens known as an intraocular lens implant or IOL, is then inserted in its place. This operation is carried out under sterile conditions in the operating theatre. The cataract has its own covering which is called a capsule. The cataract is removed from the capsule which is left behind, as this is needed to hold the artificial lens implant in place. If you would like to watch the operation, you can do so by logging on to the Eye & Ear Hospital website which contains a video of cataract surgery being performed. The web address is

What happens before my operation?

You will have a special scan called an A-scan to measure the best strength IOL for your eye. This is usually done on a Thursday morning in my rooms in Rathgar.

You will have received a date for your surgery once you have decided to go ahead with the operation. I will do your surgery in Mount Carmel Hospital or in the Royal Victoria Eye & Ear Hospital.

The surgery is performed as a day case procedure in most cases.

What happens when I go into hospital to have my cataract surgery?

After you have been admitted to your bed, the nurses will start to put drops in your eyes to dilate your pupils and prepare your eye for surgery. These drops may sting your eye for a few seconds after going in. This is normal and nothing to be alarmed about.

You will be one of 7 or 8 people on the list to have your surgery done, so there may be a waiting period before you are brought to theatre.

Once you arrive in the operating theatre the nursing staff will help you onto the operating table. Once you are lying in a comfortable position, some monitors will be placed on your chest and finger. These are routinely used on every patient to monitor their heart and oxygen levels during your surgery. You will also have a blood pressure cuff on your arm to monitor your blood pressure. This feels very tight during a blood pressure check, but is nothing to be concerned about.

The anaesthetist will then put a small needle in your hand or arm so that he/she can give you some medication to make you feel relaxed and to prevent you from feeling any pain during the procedure. He/she will then put some anaesthetic drops in your eye to make it become numb.

Your operation will then begin. You will notice a very bright light, and will feel me gently leaning on your forehead. You may feel some water trickling down the side of your face during the procedure. This is normal. The machine used to remove the cataract is a little noisy, but only for a minute or two. Once your operation is over, we will put a plastic shield over your eye to protect it. You are then brought to the recovery area for a short while before being transferred back to your bed.

Once you return to the ward, you will be given something to eat and drink. You will also be given two tablets to take. These are to prevent the pressure in your eye from increasing. You will be given two more of these to take 4 hours later. Once you are ready, you can go home. You will be given a prescription for eye drops which you will be using for the next 3-4 weeks. You should leave the eye shield on until the following morning. It can then be removed and kept to cover your eye at night time for the first 2-3 nights.

How should my eye feel after surgery and what can I expect to see?

Your eye will feel gritty as if there is something in it. This feeling will last for up to several weeks and at worst several months. This is normal and will eventually settle. Some people will not have this sensation. Your eye may also be watery and red. This is also normal and will eventually settle down.

Immediately after your operation your vision will be blurred, but this will begin to improve over the next few days. You will not be able to read or see close up, as you will need new glasses. These will be prescribed by your optician approximately six weeks after the operation.

What are the potential complications of cataract surgery?

All surgery has potential complications. Most people have no complications during surgery, but it is important for you to understand the possible risks involved.


There is a 0.5 – 0.3% risk of infection. If this occurs is untreated, it can be devastating in that it can lead to loss of an eye. This potential complication is therefore taken extremely seriously and everything possible is done to prevent this from happening. An iodine based cleaning agent is used to sterilise the eye at the beginning of the procedure, which is carried out in a sterile environment. At the end of the procedure an antibiotic is put inside the front of your eye. You will be given drops to use after the operation as explained previously, these contain an antibiotic to further reduce the risk of infection, and it is most important that they are used as directed. The symptoms of infection include severe pain and your vision getting worse. If you should experience any of these symptoms you should contact the ward staff nurse immediately, and he/she will arrange for me to speak to you. If you do get an infection inside your eye post operatively, you will be admitted to hospital immediately for treatment. 

Expulsive Haemorrhage: 

There is a very small risk of bleeding inside the eye during the surgery. In very rare situations that can lead to loss of the eye. With the modern type of small incision cataract surgery, this risk is very low. If haemorrhaging inside your eye occurs during the surgery, the operation is suspended immediately and the wound is stitched closed to prevent the haemorrhage from spreading. Once things have settled, you are brought back to theatre a few weeks or months later to complete the procedure.

Corneal oedema: 

Some people will experience blurred vision after surgery due to “water logging” of the cornea post operatively. This will eventually settle down. Very rarely, in some cases a corneal graft may be required.

Leaky wound: 

If the incision is leaking after surgery, I may need to put a contact lens into your eye until the leaking stops. Rarely, you may have to have a stitch.

Subconjunctival haemorrhage: 

This looks dramatic, but is not serious at all. If a tiny blood vessel in the transparent covering over the white of your eye bleeds, this part of your eye becomes completely red. This is basically a bruise, and is nothing to worry about. It will disappear on its own over time.

Dropped nucleus: 

Sometimes during surgery the capsule of the lens can get torn, and if this happens early on in the procedure, some or all of the cataract may fall into the back of your eye. If this happens, the surgery is completed without removing the fallen piece of cataract. This is best removed on a separate occasion by a vitreo-retinal specialist in order to avoid damage to the retina. This will be organised within the next day or so and is a very successful procedure.

Capsule thickening: 

The cataract has been removed, and its natural capsule has been left behind in order to support the new lens implant. This capsule is transparent. However, it may become thickened and opaque after weeks, months or years after surgery. If this happens, your vision will become blurred. This condition is treated with laser. This is done in my rooms, it is painless, and is covered by your private health insurance.

Cystoid macular oedema:   

Occasionally after cataract surgery, fluid can accumulate at the back of the eye. Should this happen you will notice that your vision is blurred. This condition is successfully treated with eye drops and tablets for 3-4 weeks.

Retinal detachment:   

This is a rare complication and can happen many years after surgery. It is treated surgically by a vitreo-retinal surgeon.

Last updated 21 September 2016 by School Web Administrator.