An eye image

Anaesthesia for cataract surgery

If you are having cataract surgery, you may want to know more about the anaesthetic choices available to you. It is important to discuss the options and what anaesthesia you would prefer with your consultant and/or nurse at your clinic appointment or at the pre-assessment discussion.

Anaesthetic drops

Anaesthetic eye drops are used in all cataract surgeries as they numb the eye for the procedure very effectively and wear off quickly after the surgery.

Sub-Tenon block

Sub-Tenon anaesthesia, also called a sub-Tenon block or “eye block” is another form of local anaesthesia given after numbing eye drops are applied. Numbing medication is given in one corner of the eye under the eyelid, not directly into the eye but around it, and it is not given with a needle. As it is given, you may feel pressure or a mild stinging sensation for a few seconds. This anaesthetic makes the eye completely numb which means the eyelids will be relaxed and not squeezing. This anaesthetic will also make the vision very blurred and numb the muscles around the eye helping to keep the eye from moving. The sub-Tenon anaesthetic takes approximately 4-6 hours to wear off after the surgery and during this time the eye will have a pad on it.

Both anaesthetic eye drops and sub-Tenon blocks are included within Moorfields Private’s package price for cataract surgery when they are provided by a surgeon.


If you would rather not be aware of the surgery whilst it takes place, intravenous sedation may be offered to you. This is where a consultant anaesthetist gives you sedative medications through a cannula, usually placed in a vein on the back of your hand. There are different levels of sedation. In all cases, sedation will make you relaxed and less aware of your surroundings during the operation. The higher the level of sedation, the less aware you are and the less you remember of the procedure. If you opt for higher or “deeper” level of sedation, it is best to have it on an empty stomach to avoid food regurgitation which can happen as a result of muscle relaxation. A nurse will apply a numbing cream to the back of your hand, so you don’t feel the cannula. You will receive your sedation before the start of the surgery.

Sedation wears off within a couple of hours and should not delay your discharge from the hospital, but it is advisable to arrange for someone to take you home after your operation or be able to take a taxi home.

In almost all cases, sedation is preferred over General Anaesthesia, particularly for people with health problems affecting the heart or lungs. General Anaesthesia has much higher risks compared to sedation. During sedation, patients can breathe on their own and this makes it a much safer option.

Surgery under General Anaesthesia is when a patient is asleep and completely unaware for the whole procedure. It is usually reserved for children and young patients without heart or lung problems who may be unable to cooperate, lie still or if they suffer from severe anxiety. It is much more invasive and requires the patient’s breathing to be taken over whilst the patient is unconscious during the surgery. It takes longer to recover after the surgery and be ready to go home. A consultant anaesthetist administers the general anaesthetic and monitors the patient’s vital signs throughout the operation. It is important to consider your overall health when thinking about having general anaesthesia.

Both sedation and General Anaesthesia require a dedicated consultant anaesthetist present throughout your surgery.

Whichever anaesthetic option you choose following discussion with your consultant for your cataract surgery, it will be the most suitable for your comfort and health.

Your surgeon may recommend working with a consultant anaesthetist to help look after you during surgery, to give your eye block and provide sedation as required.

Ionides, Alex

Written in association with

Mr Alexander Ionides

Consultant Ophthalmic Surgeon and Clinical Lead

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