Cataract Surgery Complications

Dr. Russel Lazarus, November 11, 2020

Every year, over 9.5 million cataract surgeries are performed, worldwide.

While the overwhelming majority (98%) of cataract surgeries are successful, like any surgical procedure there are risks involved.

It is important to understand these risks and be able to recognize the symptoms that may require immediate medical attention following your procedure.

While complications can arise both during and after cataract surgery, most are not life threatening or vision threatening and can be effectively treated with medical or surgical intervention.

Secondary cataract

During cataract surgery, only the anterior (front) part of the eye’s lens capsule, the “bag” that holds the lens in place, is removed— while the posterior (back) part of the lens capsule remains intact. Then, the entire eye lens is replaced with a clear artificial lens.

A secondary cataract, also called a posterior capsule opacification (PCO) occurs when the posterior part of the capsule becomes cloudy. This is the most common complaint following cataract surgery, and can occur from a few months to a few years post-operation.

With a quick and painless in-office procedure, called a YAG laser capsulotomy, your eye doctor can easily correct the condition by removing the PCO. During this procedure, your eye doctor will insert two different types of eye drops, to dilate your pupils and to reduce any corneal inflammation.

Using a laser, your eye doctor will then break up the new cataract of the posterior capsule to allow light to pass through for clearer vision.


If bacteria enter your eye during surgery, you can develop an infection. While this is uncommon, it can cause serious complications. It is therefore important to recognize the signs of an infection and seek immediate treatment.

Symptoms of infection include:

  • Eye pain
  • Red eyes
  • Light sensitivity
  • Blurred vision

An antibiotic medication is the most effective treatment for a bacterial infection. If your eye becomes infected post-surgery, your eye doctor may prescribe an antibiotic that is directly injected into your eye.

To stop the infection from spreading, your eye doctor may also remove the vitreous of your eye, the clear gel-like matter that fills the center of your eye, and replace it with a new gel that is free of bacteria.

Contact an eye doctor near you, to find out more about cataract surgery.

SEE RELATED: What are Cataracts?

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Eye swelling is not usually a cause for concern following a surgical procedure, though excessive swelling requires a call to your eye doctor.

If you notice that your eye continues to appear swollen after a couple of days, contact your eye doctor.

Your eye doctor can prescribe an anti-inflammatory eye drop or medication to help reduce the swelling.

Retinal detachment

If your retina pulls away from its normal position on the posterior wall of your eye, retinal detachment can occur.

This condition requires immediate medical attention, as it could threaten permanent loss of vision.

If you notice any of the following symptoms, contact an eye doctor immediately:

  • Loss of vision
  • Floaters in your visual field
  • Flashes of light

Lens fragments

During cataract surgery, the eye’s lens is removed and replaced with a new artificial one. During removal, fragments from your old lens may fall into the back of your eye and get lodged there. This can cause retinal and corneal inflammation, high eye pressure, and even permanent vision loss.

To remove the lens fragments and protect your eye, a second surgery will be required.

Increased retinal fluid (bleeding)

Bleeding during surgery is rare, but can occur if the retinal blood vessels begin to leak. Mild bleeding is not a cause for concern, but moderate to severe bleeding that leaks into the space between the cornea and iris, can cause vision loss.

Many times, this condition can be treated with eye drops and typically does not cause any permanent vision problems — though it can take a couple of months to heal.

However, if the eye drops are not effective in helping the blood drain from your eye, the blood accumulation can lead to eye pressure build-up and steroid eye drops and/or surgery may be required.

Dislocated intraocular lens (IOL)

If the artificial lens (also called the intraocular lens, IOL) that is implanted into the eye moves from its correct position, it can cause blurry or double vision. In severe cases, a dislocated IOL can cause swelling and bleeding.

In mild cases, the IOL can be easily repositioned without the need for a second procedure. However, in severe cases, surgery to reposition the lens, sew it into place or implant a new one, may be necessary.

Repositioning the IOL should be done as soon as possible following cataract surgery to prevent the implant from scarring into place— this usually happens after about three months post-surgery. Once the implant has scarred into place, it becomes more difficult to remove.

Corneal swelling

Following cataract surgery, it is not uncommon for the cornea to become inflamed. This can affect your vision clarity and be quite uncomfortable.

While this generally disappears after a few days or weeks, your eye doctor can prescribe anti-inflammatory eye drops to help reduce the swelling and improve vision.

Posterior vitreous detachment (PVD)

If you notice floating spots that look like spider webs and flashes of light after surgery, you may have a condition called posterior vitreous detachment (PVD)— when the vitreous detaches from the retina.

This condition generally heals on its own within a couple of months, but since the symptoms can be similar to retinal detachment, it is critical to seek immediate medical care.

Increased eye pressure

Eye surgery can cause a condition called ocular hypertension, in which the intraocular pressure rises to the point that your vision is affected. Any ocular bleeding, swelling, or pieces of lens fragments left in the eye, can cause this increase in eye pressure.

If this occurs, your eye doctor may prescribe eye drops, eye injections, or oral medication.

In general, high intraocular pressure can lead to glaucoma, a serious sight-threatening disease. Therefore, it is important to follow up with your eye doctor following your cataract surgery to ensure that your eye pressure remains within normal limits.


Photophobia, also known as increased sensitivity to light, is a normal side effect post cataract surgery.

However, if this symptom lasts more than a few days, it is important to follow up with your eye doctor, as it can indicate ocular swelling that requires treatment.

Ptosis (droopy eyelid)

Ptosis is a common side effect following ocular surgery, especially if the eyelids were stretched into an open position for an extended amount of time.

When caused by surgery, ptosis will typically disappear on its own after a couple of months. However, if you notice that your eyelid continues to droop after around six months, surgery may be necessary to strengthen the muscles that lift the eyelid, in order to return it to its correct position.


This condition causes visual disturbances following cataract surgery. There are two primary visual disturbances that can develop:

  • Negative visual disturbance: A curved shadow appears within the field of peripheral vision
  • Positive visual disturbance: Halos, flashes, starbursts, and streaks of light appear within the visual field

It has yet to be discovered what causes these visual disturbances, but the condition generally goes away on its own.

If it lingers more than a few months, your eye doctor may recommend eye drops, prism lenses, or a second cataract surgery to replace the IOL with a new one.

LEARN MORE:  Guide to Eye Conditions

If you are thinking about cataract surgery, discuss the benefits and possible risks and complications of the procedure with an eye doctor near you

Most cataract surgery complications can be treated successfully without threatening your vision, but don’t hesitate to discuss any concerns you may have with your doctor— especially if you have any other health or ocular conditions.

With a 98 percent success rate, the benefits of cataract surgery and improved vision may outweigh the risks of the procedure.