Following cataract surgery, a minority of patients may experience the onset of cloudy vision. This is caused by posterior capsule opacification (PCO) and is sometimes known as a ‘secondary cataract’. PCO is one of the most common cataract surgery complications, but affects fewer than 10% of all patients and is easily treated.

It occurs when a membrane grows in the lens capsule, over the artificial intraocular lens that was inserted during cataract surgery. Posterior capsule opacification typically develops within two years of the original cataract surgery procedure.

PCO can be treated with a simple and quick procedure. Using a laser, the surgeon removes the unwanted part of the lens capsule that has grown over the lens. This is a low-risk, bladeless operation that can be completed in minutes. Eyesight should return to normal within a few days of the procedure.

Other cataract surgery complications are much more unusual. They can occur during the operation or afterwards. Most complications are not serious and can be treated or rectified with further treatment.

Possible (but rare) complications during cataract surgery include:

• Damage to the lens capsule or other parts of the eye
• Bleeding or infection
• Part of the cataract not being removed successfully

With a skilled surgeon, however, these risks are minimal. Laser assisted cataract surgery can improve success rates still further, due to its high precision and reduced risk of infection.

Sometimes, in a small minority of cases, complications can occur during recovery, or further down the line. These may include:

• Inflammation or redness in the eye that has been treated
• Retinal swelling
• Corneal swelling
• A feeling of pressure in the eye
• Drooping eyelid
• Dislocated IOL. This occurs if the artificial lens (IOL) inserted during surgery becomes dislocated and moves out of the position it was placed in by the surgeon. This rare complication can be treated with a second cataract procedure.
• Retinal detachment. This is a serious complication that requires immediate medical attention. Seek medical advice if you experience flashes, floaters or distorted vision. Retinal detachment is rare, affecting 1 in 10,000 people (and not always as a result of surgery). If seen quickly enough, most patients can have the retina reattached to restore vision.

If you are worried about any symptoms you are experiencing following cataract surgery, always get your eyes checked by your specialist.