Cataract surgery is a procedure that removes the clouded natural lens from your eye and replaces it with a clear artificial one. It’s the most commonly performed surgery in the developed world, and the standard technique takes roughly 15 to 20 minutes per eye. Most people notice sharper vision within days, and serious complications are rare.
Why Cataracts Form
Your eye’s natural lens sits behind the iris and is made almost entirely of specialized proteins arranged in a precise, transparent structure. Over a lifetime, those proteins accumulate damage from UV radiation, oxidation, and other chemical changes. The proteins gradually unfold and clump together into larger complexes that scatter light instead of transmitting it. This is what creates the cloudy, washed-out vision of a cataract.
Because the damage is cumulative, cataracts are overwhelmingly age-related. By the mid-60s or 70s, enough protein has broken down in most people’s lenses to affect vision. Less commonly, cataracts develop earlier due to diabetes, eye injuries, prolonged steroid use, or heavy UV exposure. No eye drop, supplement, or lifestyle change can reverse the protein clumping once it starts. Surgery is the only treatment that restores clear vision.
How the Surgery Works
The standard technique is called phacoemulsification. Your surgeon makes a tiny incision in the cornea, typically 2.2 to 3.2 millimeters wide. Through that opening, they create a circular window in the thin capsule that holds your natural lens. A small probe is then inserted that emits ultrasonic vibrations, breaking the clouded lens into fragments. Those fragments are suctioned out along with any remaining lens material.
Once the old lens is fully removed, a foldable artificial lens (called an intraocular lens, or IOL) is injected through the same small incision. It unfolds inside the lens capsule and stays in place permanently. The incision is small enough that it usually seals on its own without stitches.
A newer variation uses a femtosecond laser to automate some of the early steps: making the corneal incision, creating the capsule opening, and pre-softening the lens before the ultrasound probe finishes the job. This can reduce the amount of ultrasonic energy needed, but studies have not shown a clear advantage in final visual outcomes for most patients. Laser-assisted surgery typically costs more and is not always covered by insurance.
Choosing Your Replacement Lens
The artificial lens you receive determines what kind of vision you’ll have after surgery, so this decision matters. There are three main categories.
- Monofocal lenses are the most common and the most proven. They correct vision at one fixed distance, usually set for seeing far away. You’ll still need reading glasses for close-up work. Medicare and most insurance plans cover monofocal lenses.
- Multifocal lenses have built-in zones for near, intermediate, and distance vision, similar to bifocal glasses. They can reduce or eliminate the need for reading glasses. The trade-off: some people experience glare or halos around lights, especially when driving at night. These lenses are generally not recommended if you have glaucoma, macular degeneration, or other conditions that already reduce the amount of light reaching your retina. They cost more and are typically paid out of pocket.
- Toric lenses have extra correction built in for astigmatism. If you have moderate to high astigmatism, a toric lens can sharpen your distance vision significantly compared to a standard monofocal. They also carry an additional out-of-pocket cost.
What Happens Before Surgery
In the weeks before your procedure, your eye doctor will take precise measurements of your eye to select the right lens power. This process, called biometry, measures two key things: the curvature of your cornea and the length of your eye from front to back. These numbers are fed into a formula that calculates which artificial lens will give you the best focus.
Most measurements are taken with a painless optical scan. If that scan can’t get a clear reading (sometimes the case with very dense cataracts), an ultrasound measurement is used instead. If you have significant astigmatism, previous laser vision correction, or an unusually shaped cornea, your doctor may also map the full surface of the cornea with a topographer. You’ll typically be asked to stop wearing contact lenses for a period before these measurements, since contacts can temporarily alter corneal shape.
Recovery Timeline
Recovery is faster than most people expect. Many people can read, use a computer, and watch TV within several hours of surgery. Walking is fine the next day. You can shower the day after, though you should keep the water stream away from your eye directly.
During the first 48 hours, avoid bending over or putting your head below your waist, which can increase pressure in the eye. For the first week or so, hold off on anything that involves physical exertion or risk of something hitting your eye. Activities like running, golf, cycling, tennis, and sex are generally fine after 7 to 10 days. Swimming should wait at least two weeks to minimize infection risk.
Your vision may fluctuate during the first few days. For most people, it takes two to three weeks for vision to fully stabilize. Your doctor will typically see you within a day or two of surgery, then again at about one week and one month.
Risks and Complications
Cataract surgery has a strong safety record, but no surgery is risk-free. The most common long-term issue is called posterior capsule opacification. The thin membrane that holds your new artificial lens can gradually become cloudy over time, causing vision to blur again. This happens in roughly 12% of patients within the first year and about 28% within five years. It’s easily treated in the office with a quick, painless laser procedure that clears the membrane in minutes.
Serious complications are uncommon. Infection inside the eye (endophthalmitis) and retinal detachment can both occur but are rare with modern surgical techniques. Temporary side effects like dry eye, mild inflammation, and sensitivity to light are more typical and usually resolve within a few weeks. If you notice a sudden increase in floaters, flashes of light, or a shadow in your peripheral vision after surgery, contact your eye doctor promptly, as these can signal a retinal issue.
Cost and Insurance Coverage
Medicare Part B covers cataract surgery with a standard monofocal lens when performed in a hospital outpatient setting, surgical center, or doctor’s office. After you meet your Part B deductible, you pay 20% of the Medicare-approved amount for both the surgeon’s fee and the facility fee. Most private insurance plans follow a similar structure.
If you choose a premium lens (multifocal, toric, or extended depth of focus), you’ll typically pay the difference between the standard lens cost and the upgraded one out of pocket. That added cost can range from several hundred to a few thousand dollars per eye, depending on the lens and the practice. Your surgeon’s office can usually give you a specific quote during your pre-operative visit. It’s worth asking exactly what Medicare or your insurer will cover before the procedure, since some recommended services may not be included.