Cataract surgery is a 10- to 20-minute outpatient procedure where a surgeon removes the clouded natural lens from your eye and replaces it with a clear artificial one. It is the most commonly performed surgery in the world, and while the procedure itself is quick, the full process includes pre-operative measurements, choosing the right replacement lens, the surgery itself, and several weeks of recovery with medicated eye drops. Here’s what each stage looks like.
Before Surgery: Measuring Your Eye
In the weeks before your procedure, your ophthalmologist takes precise measurements of your eye to determine the correct power for your replacement lens. A device called an optical biometer measures the length of your eye, the curvature of your cornea, the depth of the space behind your cornea, and the thickness of your natural lens. These numbers feed into calculation formulas, some now assisted by artificial intelligence, that predict exactly which lens will give you the sharpest vision afterward. Getting these measurements right is the single biggest factor in your visual outcome.
You’ll also start using eye drops about two days before surgery. These typically include an anti-inflammatory drop and an antibiotic drop to prepare the eye and reduce infection risk on the day of the procedure.
Choosing a Replacement Lens
The artificial lens implanted during surgery is permanent, so this decision matters. There are three main categories to consider.
- Monofocal lenses provide sharp vision at one distance. Most people choose to have them set for distance vision and wear reading glasses for close-up tasks. These lenses produce the fewest visual side effects and tend to work best for people who drive frequently at night.
- Multifocal lenses have corrective zones built in, similar to bifocal or trifocal glasses, letting you see clearly at both near and far distances. The trade-off is a higher chance of glare and halos around lights, especially at night. They’re generally not recommended for people who also have glaucoma or macular degeneration, because they allow less light into the eye.
- Toric lenses include built-in correction for astigmatism, a condition where the cornea is curved unevenly. If you have moderate to high astigmatism, a toric lens can reduce or eliminate the distortion that would otherwise remain after surgery.
Your surgeon will recommend a lens type based on your eye health, lifestyle, and how much you want to rely on glasses afterward. Multifocal and toric lenses are often categorized as “premium” options and may carry additional out-of-pocket cost.
What Happens on Surgery Day
Cataract surgery is done at an outpatient surgery center or hospital. You’ll be awake for the procedure, but you won’t feel pain. Numbing eye drops are applied in every case. Some surgeons also use a technique called a sub-Tenon block, where additional numbing medication is placed around the eye (not with a needle and not directly into the eye) for deeper anesthesia. If you’d rather not be aware of the surgery at all, intravenous sedation through a small cannula in your hand can make you relaxed and largely unaware of your surroundings.
The actual surgery takes 10 to 20 minutes depending on the density of your cataract. Your surgeon begins by making a tiny incision in the cornea, typically between 1.9 and 2.75 millimeters wide. This incision is so small it usually seals on its own without stitches. Through this opening, the surgeon creates a round opening in the thin membrane (called the capsule) that surrounds your natural lens.
Next comes the core of the procedure: breaking up and removing the clouded lens. The standard technique, called phacoemulsification, uses a pen-sized ultrasound probe inserted through the incision. The probe emits sound waves that break the hard center of the lens into small fragments, which are simultaneously suctioned out. Surgeons use different strategies to divide the lens, such as sculpting grooves and cracking it into quadrants or using a chopping motion with a second instrument, but the goal is the same: reduce the lens to pieces small enough to suction through that tiny opening.
Once the old lens is completely removed, the surgeon folds the new artificial lens and inserts it through the same small incision. It unfolds inside the eye and is positioned within the original lens capsule, where it stays permanently.
Plan to spend roughly 30 minutes in recovery afterward as any sedation wears off. You’ll go home the same day with a protective shield over the eye.
Laser-Assisted Surgery
Some surgeons offer a laser-assisted version of the procedure. A femtosecond laser, the same type used in LASIK, can perform several steps that are otherwise done by hand: making the corneal incision, creating the opening in the lens capsule, and softening or fragmenting the cataract before the ultrasound probe finishes the job.
The laser maps the lens capsule in detail and can place the capsule opening more precisely than a manual technique. This improved centering can matter when a premium multifocal or toric lens is being implanted, since those lenses perform best when perfectly positioned. The laser also reduces the amount of ultrasound energy needed inside the eye. However, the American Academy of Ophthalmology notes that visual outcomes between traditional and laser-assisted surgery are comparable for most patients, so the laser version is typically an optional upgrade rather than a necessity.
Recovery and Eye Drops
Recovery follows a structured schedule built around medicated eye drops. A typical regimen includes three types: a steroid drop to control inflammation (used four times daily and then gradually tapered over about four weeks), an antibiotic drop to prevent infection (used four times daily for roughly nine days), and an anti-inflammatory drop used once or twice daily for a set period your surgeon specifies. Keeping up with this schedule is one of the most important things you can do to protect your result.
Most people notice clearer vision within a few days, though it can take several weeks for your eye to fully stabilize. During the first 48 hours, avoid bending over or putting your head below your waist, which can increase pressure in the eye. Activities like running, cycling, golf, and tennis are generally safe after 7 to 10 days. Swimming should wait at least two weeks to minimize infection risk from waterborne bacteria.
The Most Common Long-Term Issue
The artificial lens itself lasts a lifetime and cannot develop a new cataract. However, the natural capsule left in place to hold the lens can gradually become cloudy over time, a condition sometimes called a secondary cataract. Studies show this happens in roughly 28% of patients within two to three years, and about 50% within three to five years. In younger patients, the rate is even higher.
If this cloudiness affects your vision, it’s treated with a quick laser procedure that creates a small opening in the hazy capsule to restore clear sight. The laser treatment takes only a few minutes in an office setting, requires no incision, and the improvement is usually noticeable within a day or two. Most people only need it done once.