The core idea

Cataract surgery does not repair or clean the natural lens — it replaces it entirely. The clouded lens is broken up and removed, and a new, clear artificial lens (the IOL) is placed into the same small pocket of tissue, called the lens capsule, that held the original lens. Once healed, this new lens is permanent.

Before the day of surgery

You'll typically have a pre-operative measurement session, sometimes called a biometry exam, where the length and curvature of your eye are measured precisely. These measurements are used to calculate the power of the artificial lens that will give you the sharpest focus at your chosen target distance. This is also the point where you and your surgeon finalize which category of IOL you'll receive. Compare IOL categories →

The two most common surgical techniques

  • Phacoemulsification ("phaco"). The most widely used method. The surgeon makes a very small incision — typically around 2 to 3 millimeters — and uses an ultrasonic probe to gently break the clouded lens into tiny fragments, which are then removed by suction. The artificial lens is then folded and inserted through the same small opening, where it unfolds into place.
  • Femtosecond laser-assisted surgery ("femto"). A variation that uses a computer-guided laser to perform some of the initial steps — the incision, the opening in the lens capsule, and softening of the lens — with a high degree of precision, before phacoemulsification completes lens removal. Not every clinic offers this option, and it isn't necessary for a successful outcome for every patient; your surgeon can advise whether it's relevant to your case.

What actually happens during the procedure

  1. Preparation. Numbing eye drops (and sometimes a mild sedative) are given. Most cataract surgery is done with local anesthesia — you are typically awake, but comfortable and without pain, not under general anesthesia.
  2. A small incision. The surgeon creates a tiny, self-sealing opening at the edge of the cornea.
  3. Access to the lens. A precise circular opening is made in the thin membrane (capsule) surrounding the natural lens.
  4. Lens removal. The cloudy lens is broken up and gently removed using ultrasonic energy (phaco) or a combination of laser and phaco.
  5. IOL insertion. The new intraocular lens, folded to fit through the small incision, is placed inside the same capsule and gently unfolded into its permanent position.
  6. Closing. In most cases, the incision is small enough to seal itself without stitches.

The entire procedure typically takes somewhere in the range of 10 to 20 minutes of actual surgical time per eye, though your total time at the surgical center — including preparation and initial recovery — will be longer.

One eye at a time, usually

Most surgeons operate on one eye first, allow it to heal for a period (commonly one to a few weeks), and then perform surgery on the second eye. This staged approach lets your surgeon confirm the first eye is healing well and gives you a chance to notice how your vision responds before committing to the same lens choice, if applicable, in the second eye.

What you'll feel and see

Most patients report little to no pain during the procedure itself, thanks to the numbing drops. You may notice light, movement, or colors during surgery, but not sharp detail. Afterward, mild scratchiness, light sensitivity, and blurry vision are common in the first day or two as the eye begins to heal. What recovery looks like day by day →

Why the lens choice made beforehand matters so much

Because the IOL is inserted during this procedure and is intended to remain in your eye permanently, the decision about lens type — monofocal, enhanced monofocal, EDOF, or full-range/trifocal — is made before surgery, not adjusted afterward. That's why understanding your options in advance is worth the time it takes. Explore your IOL options →