Is this a recurrence of cataract?

No. The implant never becomes cloudy. It is the posterior capsule that becomes clouded. The correct medical term is posterior capsule opacification (PCO).

Is YAG capsulotomy painful?

No. It is pain-free thanks to an anesthetic eye drop. You perceive clicking sounds and light flashes for a few minutes.

When can activities be resumed after a YAG capsulotomy?

Immediately, except for driving for 4 to 6 hours (dilation). No time off work, no restriction on sport or swimming.

Is YAG capsulotomy covered by insurance?

Yes, it is fully covered by the French national health insurance (Assurance Maladie). Additional fees in secteur 2 may apply, often covered by supplementary health insurance.

Does the YAG laser need to be repeated regularly?

No. The capsulotomy is permanent and does not close back up. A new decline in vision should prompt a search for another cause.

Cataract · Secondary cataract

Secondary cataract: YAG laser treatment in 5 minutes

Name: Secondary cataract — YAG laser capsulotomy | Dr Tourabaly
Creator: Dr Moïse Tourabaly
Published: 2026-06-29T20:56:03+02:00
Keywords: secondary cataract yag

Is your vision becoming blurry again several months after your cataract surgery? This is most often a secondary cataract, treated without surgery by YAG capsulotomy, in the office, in just a few minutes.

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Written and medically reviewed by Dr Moïse Tourabaly · Last updated: July 6, 2026

What is a secondary cataract?

The term “secondary cataract” is well established by usage, but it is misleading: it is not a recurrence of cataract. The intraocular implant placed during your surgery cannot become cloudy again. What becomes clouded is the posterior capsule: the thin transparent membrane that sat behind your natural lens and was preserved during surgery to support the implant.

Over time, residual epithelial cells from the old lens can migrate onto this capsule and make it fibrous and opaque. This is called posterior capsule opacification, or PCO. Vision gradually becomes blurry again, as if the cataract were coming back—hence the common name “secondary cataract.”

Understand it visually

Secondary cataract and the YAG laser

The capsule that holds the implant sometimes becomes cloudy after surgery; the YAG laser reopens it in just a few minutes.

Frequency and risk factors

Posterior capsule opacification is the most common medium-term complication of cataract surgery. Its cumulative five-year frequency varies in the literature: it affects roughly 10 to 30 % of operated eyes, with wide variation depending on the patient’s age, the type of implant and the surgical technique.

The documented risk factors:

Young age at the time of surgery (patients operated on before age 50 develop PCO more often);
High myopia or pre-existing uveitis;
Poorly controlled diabetes;
Implant material and design (some square-edged models markedly reduce the risk);
Quality of capsular polishing during surgery.

Modern implants, with square edges and made of hydrophobic material, have considerably reduced the incidence of PCO compared with earlier generations. The time to onset ranges from a few months to several years after surgery.

What are the symptoms?

Patients typically describe:

Gradual decline in vision, first at night then during the day;
Return of glare, especially when driving at night;
Return of halos around lights;
“Milky” or slightly veiled vision;
Contrast and sharpness that insidiously deteriorate over a few weeks.

These symptoms resemble those of the original cataract—but here only the posterior capsule is involved, not the lens (which has been removed). A slit-lamp examination, after dilation, immediately confirms the diagnosis by visualizing the opacification behind the implant.

The treatment: YAG laser capsulotomy

The standard treatment for secondary cataract is Nd:YAG laser capsulotomy. It is not surgery but a simple laser treatment, performed in Dr Tourabaly’s office. There is no opening and no incision: the laser passes through the cornea and acts at a distance on the posterior capsule to create a central opening.

How does it work?

Instillation of a dilating eye drop (15 to 30 minutes of waiting);
Instillation of an anesthetic eye drop: the treatment is generally pain-free;
Placement of a special contact lens to properly focus the laser;
Delivery of a few dozen laser pulses to the posterior capsule to create a circular opening of 4 to 5 mm;
Total duration: a few minutes;
You leave the office immediately, with no dressing and no eye shield.

Outcome

Vision improves very quickly, often within the first few hours, once the pupil dilation has worn off. To open the capsule placed behind the intraocular implant, the pupil must first be dilated ; the laser never touches the implant itself, and the visual recovery is all the more clear-cut as a result. The result is permanent: a YAG capsulotomy does not “close back up” and requires no touch-up. A recent multicenter study confirmed a mean improvement in visual acuity from 20/40 to 20/23, with 99 % of patients satisfied and no significant complications (Lighthizer et al., 2023).

After the laser: what you should know

The YAG laser treatment requires no time off work. You can resume your usual activities (reading, screens, driving once the dilation has worn off, sport, swimming) right away. You may, however, notice in the following days:

New floaters (“flying flies”) corresponding to capsule fragments released into the vitreous. They usually resolve spontaneously within a few weeks.
A transient rise in eye pressure (rare, reversible): a tonometry check is scheduled at 1 hour and then at 1 week.
A slight halo effect around lights during the first few days.

A steroidal anti-inflammatory eye drop may be prescribed for a few days. No other treatment is needed in the vast majority of cases.

Complications and limitations — informed consent

YAG capsulotomy is a very safe treatment. The reported complications are exceptional, detailed below for the purpose of prior information:

Transient rise in intraocular pressure (< 3 %), almost always reversible;
Moderate intraocular inflammation, controlled with an anti-inflammatory eye drop;
New floaters visibly noticeable for a few weeks;
Pitting or a “pit” on the implant: a microscopic mark left by the laser, with no impact on vision;
Macular edema: rare (< 1 %), reversible with treatment;
Retinal detachment: an exceptional but real complication, the risk of which is slightly increased after capsulotomy, particularly in high myopes. It calls for an emergency consultation if light flashes, a large number of floaters, or a dark veil appear.

Dr Tourabaly systematically performs a fundus examination and an OCT before the capsulotomy to screen for any peripheral retinal tear or retinal fragility that would require prior treatment.

Frequently asked questions

No. The intraocular implant never becomes cloudy. What becomes clouded is the posterior capsule surrounding the implant. The name “secondary cataract” is historical and popular, but the correct medical term is “posterior capsule opacification” (PCO).

No. The treatment is performed under an anesthetic eye drop. You only perceive small clicking sounds and light flashes. The laser lasts a few minutes, without pain.

No. There is no general anesthesia and no fasting. You can come having eaten normally and leave on your own, provided you avoid driving during the 4 to 6 hours needed for the pupil dilation to wear off.

Immediately, except for driving for 4 to 6 hours while the pupil dilation wears off. No time off work, no restriction on sport, no ban on swimming.

Yes. YAG capsulotomy is fully covered by the French national health insurance (Assurance Maladie). Any additional fees in “secteur 2” are communicated in writing and are often covered by supplementary health insurance.

No. The capsulotomy is permanent: the opening created in the posterior capsule does not close back up. Any later decline in vision should prompt a search for another cause (AMD, glaucoma, retinal disease) through a new examination.

“Membranule” is an informal word some patients use to describe the thin membrane that forms behind the implant. The exact medical term is “posterior capsule opacification”: the capsule that supports the implant thickens and blurs vision. The YAG laser (capsulotomy) opens this membrane in just a few minutes.

Recovery is straightforward: an anti-inflammatory eye drop is sometimes prescribed for a few days. Avoid driving for 4 to 6 hours, the time it takes for the dilation to wear off. Floaters (small dark spots) may appear temporarily. Seek advice if you notice a veil, a shower of dark spots or persistent flashes of light in the days that follow.

Vision blurry again after your cataract surgery?

Consultation in Cachan (94) or in Paris. The YAG capsulotomy is performed directly in the office.