Cataract surgery - How cataract surgery is performed

Before having cataract surgery, you will be referred to a specialist eye doctor (an ophthalmologist or ophthalmic surgeon) for an assessment.

The specialist will assess your eyes and general health, and particularly check for any other eye conditions that may be affecting your vision.

A member of the eye care team will take measurements of your eyes to assess the strength of the artificial lens that will replace your natural lens.

This is also a good time to discuss the procedure in detail and ask any questions.

If you have cataracts affecting vision in both eyes, surgery will normally be carried out on two separate occasions, usually 6 to 12 weeks apart.

This gives the first eye time to heal and your vision time to return. It also allows the surgeon to know your new glasses prescription in the first eye.

The procedure

Cataract surgery is a common and relatively straightforward procedure that normally takes up to 30 to 45 minutes. It is usually carried out as day surgery under local anaesthetic, which means you are awake during the procedure and you can go home on the same day.

The most common surgical technique used is known as phacoemulsification.

Before the operation, a nurse will put drops in your eye to dilate (widen) your pupil. A local anaesthetic will also be given, which can be applied as eye drops or given as an injection into the tissue around the eye.

The surgeon then makes a tiny cut in your cornea (the transparent layer at the front of your eye). A small probe that emits ultrasound waves (high-frequency sound waves) is inserted through your cornea into the eye to break the affected lens into pieces. These pieces are then liquified and sucked out. A second probe sucks out the remaining soft pieces of outer lens.

When the affected lens has been removed, the surgeon inserts a small plastic lens in its place. The replacement lens is usually curled up in an injector and injected through the cut in the cornea. When it is in place, it unfolds itself and adopts the natural position of the old lens.

In a few cases, it may be necessary to make a slightly larger incision in the eye to replace the affected lens, which may need to be closed with tiny stitches that are removed a few weeks later. 

Replacement lenses

When the cloudy lens is removed, it is replaced with an artificial clear plastic lens. This replacement lens is called an intraocular implant, or intraocular lens (IOL).

There are three types of IOL available:

• fixed strength (monofocal) lenses, which are set for one level of vision, usually distance vision – these are used in the vast majority of cataract operations
• multifocal lenses, which can be set at two or more different strengths, such as near and distance vision
• accommodating lenses, which allow the eye to focus on both near and distant objects, in a similar way to a natural lens

Using multifocal or accommodating lenses can potentially reduce the chances of needing reading glasses after surgery, although most people will need to wear glasses in some situations after surgery regardless of the type of lenses they had fitted.

Multifocal and accommodating lenses are also not usually available on the NHS. Ask your ophthalmologist about the type of lenses available in your area before having surgery. If NHS funding is not available for the type of lens you want, you may be able to have it by paying for the cataract surgery privately.

After surgery

Most people are able to go home a few hours after having cataract surgery, although you will need to arrange for someone to collect you and take you home. You will usually go home with a pad over your eye.

It is also a good idea to arrange for someone to help look after you when you get home, as you may feel out of sorts for 24 hours.

If the vision in your other eye is poor, you may struggle with your vision for the first few days as it settles down. It's likely you will experience some discomfort in and around your eye after the procedure, but this should improve within a few days.

Complications in the days and weeks after surgery are rare, but you should contact the hospital as soon as possible if you experience increasing pain or vision loss at any point.

Read more about recovering from cataract surgery and the risks of cataract surgery.