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What are the risks of cataract surgery?

All eye operations involve some element of risk to your vision. However, over 98% of patients who have cataract surgery have a successful outcome. The important risks are listed below.

Tears to the posterior lens capsule

This may occur in about 2% of patients' eyes. It is not usually associated with a poor visual result and an intraocular lens implant can usually be inserted into the eye. Occasionally, a small piece of lens fragment may fall back into the main cavity of the eye. If this happens another operation may be needed to remove it.

Endophthalmitis (infection within the eye)

This is a rare but serious complication which can result in visual loss. It occurs in about 1 in 1500 cataract operations. The first symptoms are increasing blurred vision and redness and pain in the eye. If you experience these symptoms you should contact the eye department without delay.


Bleeding within the eye during surgery is very rare and unpredictable. If the bleeding is localised, the eye may recover but in some cases, severe visual loss may occur. Bleeding may also occur after the local anaesthetic injection into the eye socket. If this happens your operation will be postponed to another date. Usually, if the bleeding is mild a full recovery is expected but in some rare cases the blood will have to be released immediately with a small operation to prevent further loss of vision.

Retinal detachment

A retinal detachment occurs when the fluid from the cavity of the eye passes through a tear in the retina and separates the retina from the wall of the eye. Cataract surgery increases the risk of retinal detachment especially in shortsighted eyes. If you notice new symptoms of flashing lights, seeing floaters or a curtain over your vision, contact us immediately.

Macular oedema

The most sensitive part of the retina is called the macula. It allows us to see fine detail. After cataract surgery fluid may collect at the retina for no apparent reason or as a result of inflammation. It usually resolves spontaneously but may cause a prolonged visual disturbance.

Posterior capsular opacification

Thickening of the posterior lens capsule may occur in 50% of patients up to five years after cataract surgery. Instead of being like transparent polythene, this membrane becomes cloudy, reducing the amount of light getting to the retina. The vision may become blurred again rather like having the original cataract. Visual loss months or even years after cataract surgery is most commonly caused by this. It is easily treated with a small laser procedure in the outpatient department which restores the vision.

Will I need to wear glasses after having my cataract removed?

Yes. Your surgeon will try to make your distance vision as good as possible without glasses but you will almost certainly need reading glasses. Sometimes patients will need a small spectacle prescription to sharpen up the distance vision as well . Your individual visual requirements will be discussed with you before surgery by the surgeon but most patients prefer not to wear glasses for distance but to use them for reading rather than vice-versa.

When should I go to the optician?

Do not go to the optician until you have been seen in the clinic after the operation. Your eye doctor will tell you when you should get new glasses but it is usually about three or four weeks after surgery. Before this you may use any glasses that you feel are helpful. If you are particularly keen to read as soon as possible, you may use some 'temporary' off the peg reading glasses that you may buy from chemists and department stores. Using the 'wrong' glasses will not do the eye any harm.


Cataract surgery has improved greatly over the last ten years due to advancing technology. It is not a painful or worrying procedure to have done and it is associated with a high level of patient acceptability. Success rates are high with few complications. The visual results are excellent if the patient has no other eye conditions or any of the rare complications.


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