Traumatic cataract: clouding of the lens after an eye injury

A cataract is a cloudy area in the lens of the eye. NICE Clinical Knowledge Summaries describes it as an opacity that forms within the lens and can reduce its transparency, affecting vision. The NHS describes cataracts as the lens becoming cloudy, causing blurred vision and loss of sight. The lens sits behind the pupil and focuses light onto the back of the eye, so when it clouds, less clear light gets through.

Most cataracts come with ageing, and they are most common in people over 60. Trauma is a different route. NICE CKS lists trauma, as a result of injury or an eye operation, among the other causes or contributory factors for cataracts. The NHS lists having had an eye injury or eye surgery in the past among the reasons you may be more likely to get cataracts. A traumatic cataract is therefore a cataract in which the injury is thought to be the main reason.

The pages read for this guide describe the general condition rather than the detailed mechanics of injury-related cataracts, and they do not give figures for how often they follow particular injuries or how soon. For that reason, this page keeps to what the NHS and NICE say and points you to a specialist for questions about your own eye.

The NHS describes cataract symptoms as usually developing slowly. They can be in one or both eyes, and may differ between eyes. The list includes blurred vision, difficulty seeing at night, difficulty reading and watching television, eyes uncomfortable in or sensitive to light and glare, double vision in one eye, seeing glowing rings (halos) around lights and colours that look faded, especially blue. People who wear glasses may find their prescription changes more often than usual.

NICE CKS says the main symptom in adults is a gradual and painless reduction in visual acuity, with glare often dominant at first, for example in bright sunshine or from oncoming headlights while driving at night. After an injury these symptoms can be mixed with those of other injury-related problems, which is why a new change in vision should always be checked rather than assumed to be a cataract.

A cataract that develops after an injury is not an emergency in itself, but the injury that caused it may be. The NHS eye injuries page says to go to A&E or call 999 if a strong chemical such as oven cleaner or bleach is in your eye (keep rinsing with water while waiting for help and take the container), a sharp object has pierced your eye, something has hit your eye at high speed such as when using power tools or mowing the lawn, there are any changes to your sight after an eye injury, you have severe eye pain, a headache or sensitivity to light, you feel or are sick after the injury, you cannot move your eye or keep it open, or blood or pus is coming from it.

The NHS says not to drive yourself, to bring any medicines you take, not to try to remove an object that has pierced the eye, and not to touch or rub the eye. For a less severe injury that is not getting better after 24 hours, or if you are worried, it advises an urgent GP appointment or NHS 111, and says always to call 111 for a child under 5. An optician can also advise.

• Rinse a chemical splash with clean, not hot, water for at least 20 minutes, as the NHS describes.

• Do not wear contact lenses or make-up around the eye until it has recovered.

• Seek help again if vision changes later, even if the first injury seemed minor.

NICE CKS advises that an adult with a cataract should be encouraged to have an eye examination by an optometrist to assess visual acuity, with and without correction, and to exclude other causes of visual impairment. The NHS says if an optician thinks you have cataracts, they refer you to an eye specialist for more tests or treatment.

Referral for surgery is based on a discussion that covers how the cataract affects vision and quality of life, whether one or both eyes are affected, what surgery involves including risks and benefits, how life might be affected if you choose not to have surgery, and whether you want it. After an injury, an eye specialist will also want to know about any other damage within the eye, which can affect both the surgery and the likely result.

The NHS says cataracts do not usually need treatment straight away, and that stronger glasses and brighter light for reading may help for a while. Over time they get worse and surgery is the only way to remove them. For adults the decision depends on how cataracts affect daily life and whether one or both eyes are involved.

The NHS describes cataract surgery as replacing the cloudy lens with an artificial one. It is usually done in hospital under local anaesthetic, given as drops, an injection or both. The surgeon makes a tiny opening in the front of the eye, may use ultrasound to break up the lens, removes it with suction and places a clear plastic lens in the lens capsule. The operation usually takes between 20 and 45 minutes, stitches are usually not needed, and most people go home the same day, although they should not drive themselves.

Recovery involves eye drops for about 4 weeks, a possible shield at night, and avoiding rubbing the eye, driving until vision is back to normal, heavy lifting, sport, eye make-up, water in the eye and swimming. You may still need glasses for reading or distance. Surgery after an injury can be more complex than routine surgery, but the NHS pages do not detail this, so it is a question for the surgeon.

The NHS says serious complications are rare. They include vision problems such as cloudiness, blurriness, dark shadows or areas of light, and eye problems including a detached retina, infection, bleeding or inflammation, or problems with the position of the new lens. Sometimes vision becomes cloudy months or years later, which may be posterior capsule opacification.

The NHS advises seeing an optician if vision gets cloudy or blurry, you find it hard to focus, the eye becomes red or painful, you see light or dark areas, or bright light becomes uncomfortable. It advises getting help from NHS 111 if floaters suddenly appear or increase, you get flashes of light, a dark curtain or shadow moves across your vision, or your vision gets suddenly blurred, as these could be signs of a detached retina.

The NHS says you may still be able to drive if your vision is good enough, but you must tell the DVLA if your eyesight does not meet the minimum standards for driving. Ask an optician if you are not sure. Without treatment cataracts will eventually cause sight loss, and the NHS notes that for most people surgery improves vision and recovery is quick.

Protecting the eyes in future matters after an injury. The NHS list of causes also includes unprotected exposure to a lot of sunlight and smoking, both of which are modifiable. Sunglasses and eye protection for DIY and garden work are sensible habits for anyone, and particularly for someone who has already had one eye injury.

On the NHS, an optician or GP refers you to an eye clinic, and urgent injuries are seen in A&E or an eye casualty department. The NHS says there may be a wait for cataract surgery, and that your eye specialist can tell you how long. Private ophthalmology can shorten the wait for surgery and offers a wider choice of lens types, but injury-related cataracts are often better dealt with by a surgeon who can also manage any other damage, whichever setting you use.