Cataract surgery lens choices: monofocal, toric, EDOF and multifocal implants

The NHS explains that cataract surgery replaces the cloudy lens with an artificial one, placed inside the lens capsule. Moorfields Private describes it as a clear, plastic-like intraocular lens, or IOL, that lasts a lifetime and cannot be seen or felt afterwards, and says some IOLs also correct astigmatism and reduce reliance on glasses for certain tasks.

That last point is why lens choice matters. The old natural lens focused light; the new one has to be chosen to do the same job. NICE asks clinicians to discuss the refractive implications of different intraocular lenses with each person at the pre-operative assessment, to base the choice of lens on the person's chosen refractive outcome, and to record that discussion and the person's choices in the medical notes.

Moorfields Private lists the main types, which this table summarises in plain terms:

In a patient video, an NHS eye hospital explains that the lens provided on the NHS is of one focal power. If you aim for improved distance vision you will need reading glasses afterwards; if you choose to stay short-sighted so that you see close up without glasses, you will need glasses or contact lenses for distance. It says the NHS's primary focus is to remove the cataract, not to guarantee spectacle independence.

The same source describes monovision, in which one eye is set for distance and the other for near, for people who want to be less dependent on glasses. You would still need glasses for longer periods of reading and for night driving. It also says toric lenses may be available on the NHS at its own sites if astigmatism is 1.75 dioptres or more, which is that hospital's threshold rather than a national rule, so ask your own hospital what it offers.

It also says there is no facility to top up on the NHS to have a private lens fitted during an NHS operation; if you go privately you would arrange the review privately and some tests may be repeated.

Moorfields explains astigmatism as an eyeball that is more rugby-ball than football shaped, so a standard monofocal lens may not fully correct the vision and you may need glasses for distance and near after the operation. Toric lenses are special lenses that aim to reduce astigmatism, and it says they suit people with regular astigmatism. A private cataract provider says toric lenses are not usually offered on the NHS unless there is a specific medical justification, but this varies, so ask.

NICE says corneal topography should be considered for people with significant astigmatism, irregular corneas or earlier corneal refractive surgery, which is part of the planning for a toric lens.

Premium lenses aim to widen the range of vision without glasses. A private provider's guide describes multifocal and trifocal lenses as splitting light into several focal points, and says glare, halos around lights at night and reduced contrast sensitivity are more common with them. It adds that EDOF lenses do not usually give as sharp near vision as trifocals but may cause fewer visual side effects. This is a commercial provider's educational page, so treat its comparisons as one view and ask your surgeon for the evidence that applies to you.

Moorfields Private says not all lens options suit every patient, that the best choice depends on eye health and existing conditions, and that the surgeon will discuss potential side effects. A common practical example: a private provider notes that simple monofocal lenses are predictable and may be the sensible choice for people with other eye conditions such as macular degeneration, glaucoma or diabetic retinopathy, which can limit the benefit of premium lenses. Your own ophthalmologist, not a general article, decides what is suitable.

NICE sets out how lens power is worked out and checked. It advises using optical biometry to measure the length of the eye and keratometry to measure the curve of the cornea, choosing a calculation formula according to eye length, and advises that after previous laser or other corneal refractive surgery, results are difficult to predict and further surgery may be needed if you do not want to wear glasses for distance.

To prevent wrong-lens errors it asks for the right patient notes and biometry to be checked, a surgical safety checklist adapted for cataract surgery, and the chosen lens and at least one identical spare plus alternatives to be available in theatre. NICE also says that if both eyes are operated on at the same session, it is not possible to choose a different lens based on the outcome in the first eye.

Moorfields Private says standard monofocal lenses are generally the least expensive option and are typically included in NHS cataract surgery and in its fixed package price, that premium lenses cost more because of more advanced optical engineering, that cost varies by manufacturer and design, and that choosing a toric implant usually increases the overall cost. This page does not quote prices, because they vary between providers and over time: ask for an itemised quote that states which lens is included.

A short list based on the points above:

• Which lens is included in the price or on the NHS, and what would an upgrade add?

• How much astigmatism do I have, and would a toric lens make a meaningful difference?

• Would I be comfortable wearing glasses for some tasks, or is being glasses-free essential?

• Do I drive at night, and how might halos or glare affect me?

• Do I have any other eye condition that affects which lens suits me?

• What are my options if the result is not what was planned?