Cataract surgery

An age-related cataract, seen under the microscope



A cataract is a cloudy lens in your eye, which can make it difficult for you to see well enough to carry out your usual daily activities. If the cataract is not removed, your vision may stay the same, although it will usually worsen with time. Waiting for a longer period of time until you decide to have surgery does not normally make the operation more difficult.



Cataract surgery


The purpose of the operation is to replace the cloudy lens (cataract) with an artificial lens implant inside your eye. One major advantage of private cataract surgery over NHS surgery is the ability to choose the type of lens implant that will be placed in your eye: a special multifocal lens typically allows both distance and reading vision without the need for spectacles; toric lenses can treat astigmatism, making vision without spectacles even clearer. Click on our surgeons for their experiences in the use of multifocal and toric lenses.


After your eyes have been measured for the procedure, you can relax and schedule your procedure for a time convenient to you; you can also resume contact lens wear (if appropriate) until the day prior to your procedure. On the day of your procedure, you will be greeted in reception and a nurse will then start applying eye drops to enlarge the pupil of the eye. Shortly before the procedure itself, anaesthetic eye drops and a disinfectant eye drop will be given.


The cataract procedure is usually carried out under using local anaesthetic eye drops alone, although in many cases a mild sedative is recommended to allay any anxieties you may have. With local anaesthetic you will of course be awake during the operation; you will not be able to see what is happening, but you will be aware of a bright light. If you would prefer more formal sedation or even a general anaesthetic, please discuss this with your surgeon. Many of our surgeons will play music during the procedure, which helps you to stay relaxed.


During the operation you will be asked to keep your head still, and lie as flat as possible, but we will endeavour to ensure that you are comfortable before the procedure starts. The operation normally takes 10-15 minutes, but in some cases may take up to 45 minutes. A nurse will hold your hand the whole time to make sure that you are feeling alright, but also to allow you to communicate with the surgeon, as talking unexpectedly is discouraged. Only the eye to be treated is left exposed, the rest of the face being covered up by a light drape to keep things clean.


Most cataracts are removed by a technique called phacoemulsification: a small cut (2.2mm) is made in the eye, the lens is softened with sound waves and removed through a small tube. The back layer of the lens (the lens capsule or ‘bag’), which is less than a hundredth of a millimetre thick is left behind. An artificial lens (implant) is then inserted into the bag to replace the cataract. These days, the overwhelming majority of lenses are injected into the eye through the tiny incision; the lens then opens up slowly within the eye. In rare cases, a small stitch may need to be put in the eye.


Click here for a series of diagrams showing how the procedure is performed and here for a video of surgery.


After the operation


If you have discomfort, a pain reliever such as Paracetamol every 4-6 hours is recommended (but not aspirin - this can cause bleeding). It is normal to have slightly itching, sticky eyelids and mild discomfort for a while after cataract surgery, although many patients are unaware of any unusual sensations at all. Some fluid discharge is common. After 1-2 days even mild discomfort should disappear. In most cases, healing will take about two to six weeks, after which new glasses can be prescribed, if needed.


You will be given eye drops to reduce inflammation. The hospital staff will explain how and when to use them. Please do not rub your eye, and avoid getting water into the eye in the weeks after surgery (e.g. avoid swimming).  Certain symptoms could mean that you need prompt treatment. Please contact your surgeon immediately if you have any of the following symptoms:


Excessive pain

Worsening vision

Increasing redness of the eye



Likelihood of better vision


After the operation you may read or watch TV almost straight away, but your vision may be blurred. The healing eye needs time to adjust so that it can focus properly with the other eye, especially if the other eye has a cataract.


The vast majority of patients have improved eyesight following cataract surgery.


Please note that if you have another condition such as diabetes, glaucoma or age-related macular degeneration your quality of vision may still be limited even after successful surgery.


Click here to peruse our surgeons’ outcome data.



Benefits and risks of cataract surgery


The most obvious benefits are greater clarity of vision and improved colour vision. Because lens implants are selected to compensate for existing focusing problems, most people find that their eyesight improves considerably after surgery.  However, some patients need to wear glasses for distance vision or close work following the operation; your chances of this are particular to you and will be discussed with you by your surgeon.


You should be aware that there is a small risk of complications, either during or after the operation.



Some possible complications during the operation:


Tearing of the back part of the lens capsule with disturbance of the gel inside the eye, which may sometimes result in reduced vision.

Loss of all or part of the cataract into the back of the eye requiring a further operation, which may require a general anaesthetic. Such further surgery is not always available in Hereford and may require travel to another eye unit.

Bleeding inside the eye.



Some possible complications after the operation:


Allergy to the medication used.

Bruising of the eye or eyelids.

High pressure inside the eye.

Clouding of the cornea.

Incorrect strength or dislocation of the implant.

Swelling of the retina (macular oedema).

Detached retina which can lead to loss of sight.

Infection in the eye (endophthalmitis), which can potentially lead to loss of sight or even the eye.



Complications are rare and in most cases can be treated effectively. In a small proportion of cases, further surgery may be needed and the risk of this happening is approximately 1 in 300.  Very rarely some complications can result in blindness.  Overall the risk of severe loss of vision in the affected eye is about 1 in 1000.


The most common complication is called 'posterior capsule opacification'. It may come on gradually after months or years. When this happens, the back part of the lens capsule, which was left in the eye to support the implant, becomes cloudy. This prevents light from reaching the retina clearly. To treat this, a laser beam is used to make a small opening in the cloudy membrane in order to improve the eyesight.  This is a painless outpatient procedure, which normally takes only a few minutes to perform.


We hope this information is sufficient to help you decide whether to go ahead with surgery.


Cataract surgery leaflet
Cataract surgery leaflet.doc
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Information for after cataract surgery
Information for after your cataract surg[...]
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HerefordVision Cataract Surgery Brochure
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HerefordVision Premium lenses brochure
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