Cataract Surgery Complications: Risks, How Common They Are and Warning Signs

Medically reviewed by Dr. Fouad El Sayyad, Consultant Ophthalmologist — Cornea, Cataract & Refractive Surgery · Last reviewed: October 2026

Quick answer: Cataract surgery is one of the safest operations in medicine, and serious complications are uncommon. Large registries report a tear in the lens capsule in about 1 in 100 operations, infection inside the eye in fewer than 1 in 1,000, and retinal detachment in about 1 in 500 within the first year. Most problems can be treated, especially when they are found early.

Key Takeaways

• Serious complications after cataract surgery are uncommon, and their rates have fallen over the years.
• Most early problems, such as inflammation or raised eye pressure, are mild and treated with drops.
• Later clouding of the capsule (PCO) is common and treated with a quick YAG laser.
• Your own risk depends on your eye: very dense cataracts, long (highly nearsighted) eyes, pseudoexfoliation and diabetes raise it.
• Severe pain, a drop in vision or a curtain across your vision need an urgent check.

Is Cataract Surgery Safe?

Yes. Modern phaco surgery through a small incision is performed millions of times a year, and outcomes keep improving. The Swedish National Cataract Register, with more than 2.4 million operations, found that infection inside the eye fell from 0.10% to below 0.02% and tears in the capsule from 2.8% to 0.6% over 30 years. Still, no operation is risk-free, and understanding the possible problems helps you recognise them early.

How Common Are the Main Complications?

What Can Happen During Surgery?

The most important problem during surgery is a tear in the thin capsule that holds the lens. A large European registry found it in about 1.1% of operations, with the rate falling over time. It is more likely with a very dense or white cataract, a cloudy cornea, diabetic retinopathy, a small pupil or weak lens support. When it happens, I adapt the surgery, sometimes placing the lens in front of the capsule. Most of these patients still see better than before surgery, although the risk of later problems is higher. Rarely, a piece of the lens falls to the back of the eye and needs a second operation by a retinal surgeon.

What Can Happen in the First Days and Weeks?

• Inflammation: some inflammation is expected and is controlled with the steroid drop. Do not stop it suddenly.
• Raised eye pressure: usually temporary and treated with drops; more common in eyes with glaucoma.
• Corneal swelling: blurs vision for days or weeks, especially after a dense cataract or in a weak cornea (Fuchs dystrophy). Very rarely, a corneal transplant is needed later.
• Infection inside the eye (endophthalmitis): rare, but serious. A 2022 meta-analysis found it in about 0.09% of operations overall, and about 0.05% when an antibiotic was given inside the eye. I inject an antibiotic inside the eye at the end of every cataract operation for this reason. It usually appears in the first week with increasing pain, redness and blurred vision, and needs treatment the same day.
• Dry eye: common for up to about three months and treated with lubricating drops.
• Bruising around the eye or a red patch on the white of the eye: harmless after a local block, and fades within one to two weeks.

What Can Happen Later?

• Macular oedema: swelling at the centre of the retina, usually around six weeks after surgery. It is about twice as likely in people with diabetes, and is detected with an OCT scan and treated with drops.
• Retinal detachment: in the American Academy of Ophthalmology’s IRIS Registry, it occurred in about 1 in 500 patients within a year. The risk is higher in men, younger patients, highly nearsighted (long) eyes and after a complicated operation. Flashes, many new floaters or a curtain across your vision need an urgent check.
• Clouding of the capsule (PCO): the commonest later problem. It is not the cataract coming back, and a YAG laser treatment in a few minutes clears it.
• Unwanted images (dysphotopsia): some patients notice an arc of light or a shadow at the side of their vision. It usually fades within weeks to months as the brain adapts, and only rarely needs treatment.
• Late lens dislocation: years later, the lens and capsule can slip because the fibres that hold them weaken, especially in pseudoexfoliation, high myopia or after retinal surgery.
• Residual glasses prescription: a small prescription is common and corrected with glasses; with premium lenses, it can matter more.

Who Has a Higher Risk of Complications?

• Very dense, white or long-neglected cataracts
• Pseudoexfoliation or previous eye injury, which weaken lens support
• Small pupils, including in patients taking prostate medicines such as tamsulosin, now or in the past
• Diabetes, especially with diabetic retinopathy
• High nearsightedness (long eyes)
• Corneal disease or a weak corneal endothelium
• Glaucoma, uveitis or previous retinal surgery

How Do I Reduce the Risk?

Most of the work happens before the operation. I examine every eye carefully at the slit lamp, including the cornea, the endothelium, the lens support and the ocular surface, and treat dry eye or eyelid inflammation first. I check the retina, with OCT when needed, and identify risk factors such as tamsulosin use or pseudoexfoliation so the surgery is planned for them. Surgery is performed on the Alcon Centurion under ZEISS microscopes in a sterile operating room, I give an antibiotic inside the eye at the end of every operation to lower the risk of infection, and you leave with clear instructions and a day-1 check. I do not recommend waiting for a cataract to “ripen”, because very dense cataracts are harder and riskier to remove.

Which Symptoms Need an Urgent Check?

• Severe or increasing pain
• A sudden drop in vision, or vision getting worse after it had improved
• Increasing redness or a sticky discharge
• Many new floaters, flashes of light or a shadow or curtain across your vision
• Any injury to the eye

Read the recovery timeline, the precautions after cataract surgery and what the results of cataract surgery look like.

Where Does Dr. Fouad El Sayyad See Patients?

• Sayyad Eye Center, Mohandeseen (main branch, where cataract surgery is performed): 3A Gameat El Dowal El Arabeya St., Sphinx Square.
• Sayyad Eye Center, New Cairo: Medical Park 2, opposite New Cairo Court.

To book an appointment with Dr. Fouad El Sayyad, call or WhatsApp 01000088168.

Frequently Asked Questions

What are the signs of a successful cataract surgery?

Vision that improves steadily over the first days and weeks, brighter colours, a comfortable eye and a normal eye pressure at follow-up. Mild grittiness and blurring in the first days are normal.

How do I know if something is wrong after cataract surgery?

Warning signs are severe or increasing pain, vision getting worse after improving, increasing redness or discharge, and flashes, many floaters or a curtain across your vision. Contact your surgeon the same day.

What precautions reduce the risk after cataract surgery?

Use your drops exactly as prescribed, wear the shield while sleeping for five nights, do not rub the eye, and keep water and soap out of it for one week. Attend all follow-up visits.

What is the most serious complication of cataract surgery?

Infection inside the eye (endophthalmitis) and retinal detachment are the most serious. Both are uncommon and are treated urgently, which is why sudden pain or loss of vision needs a same-day check.

What are the common side effects after cataract surgery?

Mild grittiness, watering, light sensitivity and dry eye are common in the first weeks. Some patients notice an arc of light at the side of their vision, which usually fades.

Can a cataract come back after surgery?

No. The cloudy lens is removed. Months or years later, the capsule behind the lens implant can become cloudy (PCO), and a quick YAG laser clears it.

Is retinal detachment common after cataract surgery?

No. A large US registry found it in about 1 in 500 patients within a year. The risk is higher in men, younger patients and highly nearsighted eyes.

Can complications be treated?

Most can. Inflammation and raised pressure settle with drops, PCO is treated with a YAG laser, and rarer problems such as retinal detachment or a dislocated lens are repaired with further surgery.

This article is for general education and does not replace an eye examination. Treatment decisions depend on your own eye assessment.

References

• Miller KM, Oetting TA, Tweeten JP, et al. Cataract in the Adult Eye Preferred Practice Pattern. Ophthalmology. 2022;129(1):P1–P126.
• Bro T, Behndig A, Viberg A, et al. Two point four million cataract surgeries: 30 years with the Swedish National Cataract Register, 1992–2021. J Cataract Refract Surg. 2023;49(8):879–884.
• Segers MHM, Behndig A, van den Biggelaar FJHM, et al. Risk factors for posterior capsule rupture in cataract surgery as reflected in the European Registry of Quality Outcomes for Cataract and Refractive Surgery. J Cataract Refract Surg. 2022;48(1):51–55.
• Shi SL, Yu XN, Cui YL, et al. Incidence of endophthalmitis after phacoemulsification cataract surgery: a meta-analysis. Int J Ophthalmol. 2022;15(2):327–335.
• Morano MJ, Khan MA, Zhang Q, et al. Incidence and risk factors for retinal detachment and retinal tear after cataract surgery: IRIS Registry (Intelligent Research in Sight) analysis. Ophthalmol Sci. 2023;3(4):100314.
• Fouad YA, Karimaghaei S, Elhusseiny AM, et al. Pseudophakic cystoid macular edema. Curr Opin Ophthalmol. 2025;36(1):62–69.
• Kristianslund O, Dalby M, Drolsum L. Late in-the-bag intraocular lens dislocation. J Cataract Refract Surg. 2021;47(7):942–954.
• Wanniarachchi K, Mehta JS. Management of positive and negative dysphotopsia postcataract surgery: a literature review. Taiwan J Ophthalmol. 2025;15(4):572–579.