Risks and complications

Audited results

Gresham College, 2000 years of cataract surgery.

Risk and complications

Cataract surgery is an amazingly safe procedure. More than 99% of cases result in safe removal of the cloudy cataract and stable positioning of the new lens.

A number of technical errors may occur and most are trivial and will be fixed by your surgeon as the procedure continues. The most serious complication is the rarest and this is a 1:1,000-2,000 risk of infection. In the unlikely event of this occurring, within a few days, the eye will become red, swollen and painful. The vision will become cloudy and urgent attention is essential.

Retinal detachment is also rare, but people with short-sight have the highest risk.

In a few cases the transparent membrane that supports the lens develops a tear, and additional measures to clear the vitreous jelly will be needed delaying the operation.

Audited results

We continuously audit the outcomes of our surgery.


How are we doing? What does this graph mean? The blue dots represent clusters of patients comparing their very best vision before the surgery with their best vision after surgery. 1.0 is 20/20 vision.

The post-operative visions measured at one month by independent optometrist are all in the white zone. Nobody lost vision. This is an important safety concern for all patients having eye surgery. Nearly all patients following cataract surgery had significant improvements of vision.

Some patient with very poor vision due to macular degeneration (red arrow) do not see any more letters on the chart, as would be expected. Their surgery was to brighten and improve the field of vision to help with managing everyday tasks around the home.

Some patients who started out with 20/20 vision (normal acuity) had a special type of cataract causing glare and preventing them from driving. Obviously, we can only expect normal visual acuity at best after the operation, but this is now without glare; enabling them to return to work and normal activities.