What it is
In short: a cataract is a cloudy lens inside the eye. Surgery replaces it with a clear artificial lens, and you go home the same day. Having a cataract does not always mean you need an operation straight away.
The lens sits behind the coloured part of your eye, the iris. It focuses light onto the retina, the layer at the back of the eye that senses light. When the lens turns cloudy, it scatters or blocks some of that light, so things look blurred or dim.
Cataracts often develop with age. An eye injury, some medicines and other eye conditions can also play a part.
Cataract surgery removes the cloudy lens and puts a clear artificial lens in its place. The new lens is called a lens implant, or intraocular lens (IOL).
Whether and when to have surgery depends on:
- how much your sight affects your daily life
- the health of the rest of your eye
- what you prefer
Symptoms
Cataracts usually change your sight slowly. You may notice:
- cloudy or blurred vision
- colours that look faded
- glare from car headlights
- difficulty reading in dim light
- your glasses prescription changing
- a double image when you look through one eye
Both eyes can have cataracts, but one eye may change faster than the other.
These symptoms can also have other causes. The examination shows whether the cataract is the cause. It also checks whether another part of the eye, such as the retina or the eye's surface, is involved.
Tell Dr Chin which everyday tasks have become hard, such as reading, driving at night or recognising faces. The letter chart alone does not show how the cataract affects your life.
When it is urgent
Cataracts usually develop slowly, so do not assume a sudden change is a cataract. Get your eye checked the same day if you notice:
- sudden loss of vision
- a shower of new floaters
- flashes of light
- a dark curtain across your sight
After cataract surgery, also call straight away if your sight gets worse, or the eye becomes very red or very painful.
Call the clinic at +65 6694 0400. Outside clinic hours, call the 24-hour answering service at +65 6535 8833, or go to a hospital A&E with eye services. Do not wait for a routine appointment.
What the assessment involves
At your first visit, you will have a vision test, and Dr Chin will examine the lens and the rest of the eye. You will usually have drops to widen your pupils, so that Dr Chin can see the retina at the back of the eye. The drops take 20 to 30 minutes to work and blur your sight for a few hours. Allow about 90 minutes to two hours for the visit, and arrange for someone to drive you home.
Please tell Dr Chin about:
- your symptoms
- any eye operations you have had
- your general health
- all your medicines, including eye drops
If you decide on surgery, your eye is measured to work out the power of the new lens. You will also choose where you want your sight to be sharpest after surgery, such as far away or up close. Dr Chin will explain when you may still need glasses.
Good questions to ask:
- How do my other eye conditions affect the plan?
- What can the operation do for me, and what can it not do?
Before surgery, the clinic will give you instructions about your medicines, contact lenses, and eating and drinking. These depend on your health and the anaesthesia planned, so follow the advice you are given. Do not stop any prescribed medicine on your own.
Treatment options
If the cataract is not bothering you yet
If your cataract is not getting in the way of daily life, you may not need surgery yet. Regular checks, new glasses or brighter lighting may help for a while, but they do not remove the cataract.
Sometimes surgery is suggested because the cataract blocks the view of the back of the eye. This can make it hard to check or treat a problem there.
The operation
Cataract surgery is day surgery, so you go home the same day. You have local anaesthesia with light sedation to help you relax. The eye is numbed with drops or an injection, or sometimes another type of anaesthesia is used. The plan is agreed with you beforehand.
Dr Chin makes a small opening in the eye. The cloudy lens is usually broken into small pieces with ultrasound and removed, and the new lens is put in its place. The operation itself usually takes 15 to 30 minutes.
Choosing your lens
Each type of lens has pros and cons:
- Monofocal lens: focuses at one main distance. You will usually still need glasses for other distances.
- Extended depth of focus (EDOF) lens: gives a longer range of focus, from far away to middle distances such as a computer screen. You may still need reading glasses for small print. Some EDOF lenses can cause glare or haloes (rings around lights).
- Multifocal lens: focuses at several distances, but can cause glare, haloes and difficulty reading small print in dim light.
- Toric lens: designed to correct astigmatism, a focusing problem caused by the shape of the eye. All of the lenses above are available in a toric version.
Dr Chin will discuss which lens suits the health of each eye and your day-to-day needs.
Risks
Like any operation, cataract surgery has risks, but serious problems are rare. Possible problems include:
- infection
- bleeding
- swelling
- changes in eye pressure
- retinal detachment, where the retina lifts away from the back of the eye
- problems with the position of the new lens
Some of these may need more treatment. Surgery only deals with the cloudy lens. If another condition also affects your eye, it may still limit your sight after surgery.
Recovery and follow-up
Arrange for someone to take you home after the operation. You will go home with a shield over the eye, and instructions on:
- using your eye drops, usually for a few weeks
- protecting the eye
- washing your face and hair
- when to go back to lifting, exercise, swimming and driving
Do not rub the eye. Everyone heals at their own pace, so follow the advice for your eye rather than someone else's timetable.
Your first check-up is usually the next day. Later visits check how the eye is healing and look for any problems. Once the eye has settled, you may need new glasses.
Sometimes, months or years later, the thin layer (capsule) behind the new lens turns cloudy and blurs your sight again. This is called posterior capsule opacification. See Dr Chin to have it checked. If it affects your sight, laser treatment may be an option.
Related articles
- Cataract surgery: what should I expect?
- Floaters and flashes: when should I be worried?
- Retinal detachment and tears
- All eye health articles