When is a cataract ready for surgery? Do you have to wait for it to ripen?

The old advice to wait for it to ripen

Many people in Nigeria were told by a relative, or even an older clinic, to wait until the cataract is ripe. That advice comes from a time when the operation removed the whole lens in one piece and needed a hard, mature cataract to work. Today the cloudy lens is broken up and removed through a tiny cut, and a clear artificial lens is put in its place. A softer, earlier cataract is usually easier and safer to remove.

A very advanced cataract is denser, needs more energy to break up, and carries a higher chance of complications. It also hides the back of the eye, so the doctor cannot check the retina or the optic nerve properly. Waiting too long has a cost.

Signs it is time to talk about surgery

UK guidance says the decision should not rest on a number on the eye chart alone. It rests on how the cataract affects your life. Think about whether any of these apply to you:

• You struggle to read, sew, use your phone or see the pot on the stove
• Headlights at night dazzle you, or you have stopped driving after dark
• You cannot recognise people's faces across a room or at church
• Colours look faded or yellow, or everything looks hazy, like looking through a dirty windscreen
• Your glasses prescription keeps changing and new glasses no longer help
• You have had a fall or a near miss on stairs or uneven roads
• You can no longer do your work safely

When waiting is reasonable

If the cataract is mild and you can still do everything you want, it is fine to wait. A cataract does not damage the eye while it is there, in most cases. Good light for reading, a stronger glasses prescription and sunglasses outdoors can carry you for a while. You should still have your eyes checked regularly, because vision can change.

Surgery may also be delayed if another eye problem, such as poorly controlled diabetes affecting the retina or active inflammation, needs treating first. Your surgeon will tell you if that applies.

Before you decide: the full eye check

Blurred vision in an adult is not always cataract. Glaucoma, diabetic eye disease and problems with the retina can look the same to you, and some of them are urgent. Glaucoma in particular is common in people of African heritage and often has no symptoms until late. A proper assessment checks the eye pressure and the back of the eye, and measures the eye so the right lens power can be chosen.

Avoid couching, the traditional practice of pushing the cloudy lens back into the eye with a sharp object. It can cause blindness that cannot be reversed. If a relative has had it done, that eye still needs a specialist to look at it.

One eye or both

If both eyes have cataracts, they are usually operated on separately, a few weeks apart, so the first eye has healed before the second. Many people notice how much the second eye was holding them back only after the first is done.

Common questions