Cataract and cataract surgery

What is a cataract?

The lens of the eye is a clear layer that focuses light onto the back of the eye. In a cataract, part of the lens becomes cloudy and vision becomes blurred. Most cases come with age and usually progress slowly. One eye or both eyes may be affected.

Common signs:

• Blurred vision and poor vision at night
• Difficulty reading or watching television
• Glare, and discomfort from car headlights
• Halos around lights
• Colours looking faded
• Needing a new glasses prescription often

These signs also occur in other eye conditions. Only an examination can show the cause.

Who is it for?

Surgery is suggested when a cataract gets in the way of your daily activities. It is not urgent for every patient. The sources say that waiting usually does not harm the eye and does not make a later operation harder. In some patients with a narrow angle in the eye, cataract surgery also helps treat that problem, which an eye doctor has to diagnose.

In the early stages, better light, suitable glasses or a magnifier may help. You and your eye doctor make the final decision together.

Cataract surgery does not restore vision that has been lost to another condition such as macular degeneration, glaucoma or diabetic eye damage.

How is the operation done?

The details of the operation differ a little from one centre to another and from one patient to another. In general:

• The eye is numbed with drops or an injection. You are awake and do not feel pain. Sometimes a sedative is also given.
• The surgeon reaches the inside of the eye through very small cuts at the edge of the cornea. Stitches are usually not needed.
• The cloudy lens is broken up and removed, and a clear artificial lens, called an “intraocular lens”, is put in its place.
• The operation usually takes about twenty to forty-five minutes. You rest for a while afterwards, and most patients go home the same day.
• Lenses come in different types. Some make only one distance clear, and some also correct astigmatism. The doctor suggests the suitable type based on your eye and your needs.

Before the operation the eye is measured to decide the power of the lens. See the patient guide for how to prepare for surgery.

Recovery

• Blurred vision in the first few hours is usually from the dilating drops. Discomfort in the eye may last a few days.
• Vision usually improves over a few days. Full healing can take about four to six weeks. These times vary from patient to patient.
• Use the prescribed drops exactly as instructed. A source says these drops are usually used for about four weeks, but your doctor writes your schedule.
• Do not rub your eye, do not let water or soap get into it, and do not swim until the doctor allows it.
• You may need an eye shield at night and sunglasses outdoors.
• The doctor decides when you can return to exercise, heavy work and driving.

More details are on the page “Care after eye surgery”.

Risks

Cataract surgery is described in the sources as very safe, and serious complications are rare. But every operation carries risk. Possible complications include:

• Infection inside the eye
• Bleeding or inflammation
• Swelling of the retina or retinal detachment
• Movement of the lens
• Blurring, halos, excess glare or dark shadows
• Lasting pain

Months or years after the operation, the membrane behind the lens sometimes becomes cloudy and vision blurs again. This is called “posterior capsule opacification”. It is treated with a short laser procedure. Before the operation the doctor explains the risks that apply to your eye.

When to call

After surgery, contact the doctor or the treatment centre the same day if you have:

• Pain that gets worse or is not eased by simple painkillers
• Redness that gets worse
• Falling vision

Go to the emergency department at once if you suddenly have:

• New floaters, or many more than before
• Flashes of light
• A curtain or dark shadow over your vision

For the full list, see the guide “When should I get urgent help?”.