Cataract surgery is one of the safest surgical procedures performed today. Over 90% of patients achieve 20/20 vision with glasses afterward, and the risk of the most feared complication, a serious eye infection, is roughly 1 in 8,000. That said, no surgery is risk-free, and certain health conditions or medications can shift your odds. Here’s what the numbers actually look like.
How Safe the Numbers Really Are
The best large-scale data comes from Moorfields Eye Hospital in London, one of the world’s busiest eye surgery centers. Across nearly 155,000 cataract procedures performed between 2015 and 2022, the rate of postoperative infection (endophthalmitis) was 0.012%, or about 1 in every 8,600 surgeries. That rate held steady year over year. National UK data from an earlier period showed a slightly higher rate of 0.03%, still extremely low.
Retinal detachment after surgery occurs in roughly 0.3% of cases. Swelling at the back of the eye that affects vision (cystoid macular edema) happens in up to 2% of patients, according to European Society of Cataract and Refractive Surgeons guidelines. Both are treatable when caught early. Overall intraoperative complication rates sit around 1% to 3%, and the vast majority of those complications are manageable without lasting consequences.
Common Side Effects After Surgery
Almost everyone experiences some blurry vision in the days following the procedure. This is normal swelling inside the eye and typically clears within a few days to a week. If you have a pre-existing corneal condition like Fuchs dystrophy, the swelling can take a month or longer to resolve.
Dry eye is nearly universal after cataract surgery. The procedure temporarily disrupts the tiny nerves that signal your eye to produce tears. Those nerves generally heal within about three months, but until they do, your eyes may feel gritty, irritated, or tired. If you already dealt with dry eye before surgery, expect it to be noticeably worse for that recovery window.
Mild inflammation inside the eye is also common, occurring in roughly 8% to 10% of patients in clinical trials. It’s typically managed with the anti-inflammatory eye drops you’ll already be prescribed for recovery.
The Most Common Long-Term Complication
The issue most likely to affect your vision after cataract surgery isn’t really a complication of the surgery itself. It’s called posterior capsule opacification, sometimes called a “secondary cataract.” The thin membrane that holds your new artificial lens in place gradually clouds over in up to 50% of adults within two to five years.
When this happens, your vision gets hazy again, much like the original cataract. The fix is a quick laser procedure done in an office visit that creates an opening in the cloudy membrane. It’s effective and relatively straightforward, though it carries a small risk of increased eye pressure or, rarely, swelling at the back of the eye.
Conditions That Raise Your Risk
For a healthy person with no other eye problems, cataract surgery carries minimal risk. But certain pre-existing conditions can make the surgery more complex or reduce the chances of a perfect visual outcome afterward. The distinction matters: a higher-risk surgery doesn’t mean a dangerous one, but your surgeon needs to plan for it.
Eye conditions that most significantly affect outcomes include:
- Glaucoma: roughly 2.5 times higher odds of a less-than-ideal visual result
- Age-related macular degeneration: about 3 times higher odds
- Diabetic retinopathy: ranges from 2 times higher for mild disease to over 9 times higher for the proliferative form
- Chronic uveitis (ongoing eye inflammation): nearly 4 times higher odds
- Corneal opacity: about 3.5 times higher odds
Among general health conditions, diabetes, kidney disease, and a history of stroke are the most notable risk factors. Kidney disease roughly doubled the odds of a poorer visual outcome in a large Malaysian registry study. Patients over 80 also face somewhat higher complication rates, partly because they’re more likely to have dense, advanced cataracts and other coexisting eye conditions.
How One Common Medication Changes the Picture
If you take tamsulosin (commonly prescribed for enlarged prostate), this is important to know. Tamsulosin affects the tiny muscles in your iris, and during cataract surgery it can cause the iris to behave unpredictably, going floppy, constricting, and generally making the surgeon’s job harder. This is called intraoperative floppy iris syndrome, and it occurs in roughly 86% of tamsulosin users undergoing cataract surgery.
A large Canadian study of over 96,000 men found that patients who had taken tamsulosin within two weeks of surgery were 2.3 times more likely to experience complications than those taking other prostate medications. About 1 in 255 tamsulosin users developed severe eye complications that increased the risk of needing a second surgery. Patients taking similar drugs like alfuzosin or doxazosin showed far lower rates of this problem.
The good news: when surgeons know about your tamsulosin use ahead of time, they can adjust their technique and use additional tools to manage the iris. The key is telling your eye surgeon about every medication you take, even ones that seem unrelated to your eyes.
Laser-Assisted vs. Traditional Surgery
You may have heard about femtosecond laser-assisted cataract surgery as a newer, potentially safer option. A randomized trial comparing the two techniques directly found that overall complication rates were similar. The laser group had a 2.8% intraoperative complication rate compared to 1.3% for traditional surgery, partly because the laser sometimes created incomplete openings that required manual completion. Postoperative complication rates were nearly identical: 12.5% for laser-assisted and 11.3% for traditional, with most of those being mild, temporary inflammation.
One area where the laser showed an advantage was in avoiding tears in the back capsule of the lens, which is one of the more consequential things that can go wrong during surgery. The laser group had zero capsule tears compared to 0.5% in the traditional group. Both rates are well below the national benchmark of 2%. European guidelines confirm that overall safety profiles are comparable between the two approaches.
What the Type of Anesthesia Means for Risk
Most cataract surgery today is done under topical anesthesia, which means numbing drops applied to the surface of the eye. This eliminates the risks associated with needle-based techniques like retrobulbar or peribulbar injections, which carry rare but serious risks including globe perforation, damage to the optic nerve, and bleeding behind the eye.
Topical anesthesia isn’t perfect. It doesn’t fully block sensation from deeper structures like the iris, so you may feel pressure or brief discomfort during certain steps. But it avoids the most dangerous anesthesia-related complications entirely. General anesthesia is rarely needed and is typically reserved for patients who can’t cooperate with the procedure due to anxiety, tremors, or cognitive conditions.
Warning Signs During Recovery
Most people recover without any problems, but knowing what’s normal and what isn’t can prevent a minor issue from becoming a serious one. Mild blurriness, light sensitivity, and a scratchy feeling in the eye are all expected in the first week.
What isn’t normal: sudden, severe pain that worsens rather than improves, a significant drop in vision after it had been getting better, seeing new floaters or flashing lights, or increasing redness in the eye. These can signal infection, retinal detachment, or a spike in eye pressure, all of which are treatable but time-sensitive. The first 48 hours carry the highest risk for infection, and most cases of endophthalmitis develop within the first week.