Cataract surgery: how it works, risks and what to expect

A cataract is a clouding of the lens inside the eye. It causes blurred or misty vision, glare around lights and difficulty in dim light, and mostly affects older adults. The NHS says surgery is the only way to remove cataracts.

Adults can often delay surgery unless the cataract is affecting daily activities such as reading, driving or seeing steps. Children with cataracts need surgery promptly so that vision can develop properly. If both eyes are affected, they are operated on at separate times.

Stronger glasses can help in the early stages, and the decision is usually based on how much your vision limits you rather than on a specific measurement.

Before surgery you will have your eye measured so the artificial lens power can be chosen. Lens options (single focus, extended range, toric for astigmatism) differ in how much you may rely on glasses afterwards, so it is worth asking what your hospital offers.

Take your regular medicines unless told otherwise, use any drops you are given, and arrange someone to accompany you home. You will not be able to drive that day.

The NHS describes a 20 to 45 minute operation under local anaesthetic. The pupil is dilated, the eye cleaned, a tiny cut made in the cornea, the cloudy lens broken up with ultrasound and removed by suction, and a clear plastic lens placed inside.

Most people go home soon afterwards. Vision may be blurred for hours because of the dilating drops.

The NHS lists retinal detachment, infection, bleeding, inflammation and problems with the position of the lens. It says serious complications are rare, and does not give percentages. Cloudiness can return months or years later, as posterior capsule opacification, which can be treated with a short laser procedure.

Ask your surgeon about your own risk, which is higher in eyes with other disease.

The NHS says most people recover quickly, with some eye discomfort for a few days, and eye drops for about four weeks. Do not rub the eye, lift heavy objects, play sport, wear eye make-up or get water in the eye until you are cleared. Vision usually improves over several days.

Do not drive until your vision is back to normal.

• Sudden new floaters, flashes of light, a shadow or curtain across your vision: call NHS 111 urgently.

• Increasing redness, pain or sensitivity to light: contact your eye clinic or optician.

• Cloudiness or difficulty focusing that develops later.

• Is my cataract bad enough to operate on now?

• Which lens will you use, and will I need glasses afterwards?

• Do I have other eye conditions that raise my risk?

• How soon will the second eye be done?

The technique is the same. The NHS usually provides a standard single-focus lens; private care may offer a wider range of lens types at extra cost, and quicker dates. Ask what is included, what happens if you need a laser for clouding later and how follow-up is arranged.