Phakic Intraocular Lenses (IOLs)
What Are Phakic Intraocular Lenses?
A phakic IOL is a tiny lens that we surgically place inside your eye, either in front of or behind your iris. The lens bends light rays so they focus properly on your retina. Your natural lens stays in place and continues to help you focus at different distances.
Because the phakic IOL is customized to your prescription, it corrects refractive errors just like glasses or contacts would. However, unlike glasses or contacts, you do not need to put them on or take them out each day.
LASIK and PRK reshape the surface of your cornea to improve vision. These laser procedures work well for mild to moderate prescriptions, but they have limits. If your cornea is too thin or your prescription is very high, laser vision correction may not be safe. We also discuss SMILE, another corneal laser option, when appropriate.
- Phakic IOLs can correct much higher levels of nearsightedness and farsightedness than laser surgery
- We do not remove any corneal tissue when we place a phakic IOL
- The lens can often be removed if your vision needs change in the future
- Phakic IOLs may provide sharper vision quality for people with extreme prescriptions
- Phakic IOLs avoid corneal nerve cutting, which can reduce the risk of postoperative dry eye compared with corneal laser procedures
Cataract surgery removes your cloudy natural lens and replaces it with an artificial lens. Phakic IOL surgery is different because we leave your clear natural lens in place. We perform phakic IOL surgery on younger patients who still have healthy, flexible lenses that can focus.
If you develop cataracts years after phakic IOL placement, we can remove both your natural lens and the phakic IOL and replace them with a cataract lens. This means phakic IOLs do not prevent future cataract surgery if you need it.
Anterior chamber phakic IOLs sit in the front part of your eye, between your cornea and your iris. These lenses may attach to your iris or rest in the angle where the iris meets the cornea. Posterior chamber phakic IOLs sit behind your iris and in front of your natural lens. Most modern posterior chamber phakic IOLs include a central flow feature that allows natural fluid movement through the lens, which reduces the risk of pupillary block and usually removes the need for a preoperative laser peripheral iridotomy.
- Posterior chamber lenses are the most commonly used type in 2025
- Each design has different sizing requirements based on your eye's anatomy
- Our eye doctor will recommend the best type for your specific eye structure
Angle-supported anterior chamber lenses are used far less often today because of higher risk of endothelial cell loss and angle crowding.
Who Is a Good Candidate for Phakic IOLs?
We may recommend phakic IOLs for moderate to very high nearsightedness, and for myopic astigmatism. Some phakic lenses for farsightedness exist, but availability depends on regional regulatory approvals and practice offerings. Typical correction ranges and availability will be reviewed during your consultation. The best candidates have stable prescriptions that have not changed significantly in at least one year.
Most patients who choose phakic IOLs are between 21 and 45 years old. If you are over 45, your natural lens may be starting to lose flexibility, which can affect your near vision even after the phakic IOL corrects your distance vision.
If testing shows that your corneas are too thin for LASIK or PRK, phakic IOLs can still help you. People with very high prescriptions often get better vision quality from phakic IOLs than from laser surgery. You might also prefer a reversible procedure that does not permanently reshape your cornea.
- Your prescription is higher than the safe limits for laser vision correction
- You have thin corneas or irregular corneal shapes
- You want the option to remove or replace the lens if needed
- You prefer not to have corneal tissue removed
Your eyes need to be healthy overall for phakic IOL surgery. We check that your cornea has a sufficient number of endothelial cells, which are special cells that keep your cornea clear. You also need adequate space inside your eye for the lens to fit safely without touching other structures. We follow device-specific minimums for anterior chamber depth and age-adjusted endothelial cell counts to reduce the risk of corneal decompensation or angle crowding.
We measure the depth of your anterior chamber and make sure your eye pressure is normal. Your retina should be healthy, with no tears or detachments that need treatment first. We also evaluate your pupil size in dim light because very large pupils can increase night halos and glare.
Certain eye conditions make phakic IOL surgery too risky. If you have glaucoma, chronic inflammation inside your eye, or certain corneal diseases, we may not recommend this procedure. A history of retinal detachment or very shallow anterior chambers can also be concerns.
- Uncontrolled glaucoma or elevated eye pressure
- Low endothelial cell counts in your cornea
- Active inflammation or infection in the eye
- Unstable vision prescriptions that keep changing
- Pregnancy or nursing, as hormones can affect your prescription
Pre-Operative Evaluation and Testing
Before surgery, we perform detailed measurements of your eye using specialized imaging equipment. We measure the length of your eye, the depth of your anterior chamber, and the width from side to side. These measurements help us choose the right size lens for your eye. We use anterior segment OCT or ultrasound biomicroscopy when needed to estimate sulcus-to-sulcus diameter and to plan for the desired postoperative vault, which is the clearance between the phakic IOL and your natural lens.
We also map the curvature of your cornea and examine the structures inside your eye in detail. Precise measurements are essential to ensure the phakic IOL will fit safely and comfortably. If you wear contact lenses, you will stop them before measurements to allow your cornea to return to its natural shape. Soft lenses typically require about one week, and rigid or toric lenses often need two to four weeks.
We check your eye pressure and examine your optic nerve to screen for glaucoma. A dilated eye exam allows us to look at your retina, natural lens, and other internal structures. We also count the endothelial cells on the back surface of your cornea. For patients with high nearsightedness, we carefully evaluate the peripheral retina and may treat any weak areas or tears before implantation.
- Tonometry to measure intraocular pressure
- Dilated fundus exam to view the retina and optic nerve
- Specular microscopy to count corneal endothelial cells
- Gonioscopy to examine the drainage angle of your eye
- Anterior segment OCT or ultrasound biomicroscopy when indicated to assess sulcus anatomy and lens fit
We use your prescription and eye measurements to calculate the exact power of phakic IOL you need. Advanced formulas help us predict how the lens will perform once it is inside your eye. Our goal is to give you clear distance vision, and in some cases, we may adjust the power to reduce your dependence on reading glasses later.
We also discuss your visual goals with you. Some patients prefer to aim for perfect distance vision, while others may choose slight adjustments based on their lifestyle and hobbies.
Make sure to tell us about all medications you take, including over-the-counter drugs and supplements. We need to know if you have any allergies, especially to medications or anesthesia. Discuss your visual expectations and ask any questions about the risks and benefits of phakic IOLs.
- Your complete medical and eye health history
- All current medications and supplements
- Any previous eye surgeries or injuries
- Your lifestyle, work, and hobbies that depend on clear vision
- Questions about recovery time and potential complications
The Phakic IOL Surgery
On the day of surgery, we ask you to avoid eating or drinking for a few hours beforehand if you will receive sedation. You can take most of your regular medications with a small sip of water unless we tell you otherwise. Do not drive on the day of surgery. Arrange a driver because you will receive sedation and your vision will be blurry.
We may give you antibiotic or anti-inflammatory eye drops to start using a day or two before surgery. These drops help reduce the risk of infection and inflammation. Avoid eye makeup, lotions near the lids, and lash products for several days before and after surgery to reduce contamination risk.
The surgery typically takes 15 to 30 minutes per eye. We start by making a tiny incision in your cornea, usually less than 3 millimeters wide. Next, we carefully insert the folded phakic IOL through the incision and position it in the correct location, either in front of or behind your iris.
- We numb your eye completely with anesthetic drops or an injection
- If your lens type requires it, we perform a laser peripheral iridotomy before surgery to prevent pupillary block
- A small opening allows us to insert the lens while it is folded
- Once inside, the lens unfolds and we position it precisely
- The incision is so small it usually seals on its own; occasionally a single suture is placed
Most patients receive numbing eye drops combined with mild sedation through an IV. This keeps you comfortable and relaxed while allowing you to follow simple instructions. Some patients receive a local anesthetic injection around the eye for deeper numbing.
You remain awake during the procedure, but you should not feel pain. You may notice pressure or see lights and movement, but the sedation helps you stay calm throughout the surgery.
After the procedure, we place a protective shield over your eye and observe you for a short time. Once we confirm that your eye pressure is stable and you are feeling well, you can go home with your driver. Your vision will be blurry at first, and your eye may feel scratchy or watery.
- Wear the eye shield as directed, especially while sleeping
- Start using prescribed eye drops on the schedule we provide
- Rest for the remainder of the day
- Avoid rubbing or pressing on your eye
- Avoid driving until your surgeon confirms it is safe, usually after a follow-up visit
Recovery, Results, and Long-Term Care
Many patients notice improved vision within the first day or two, although some blurriness and glare are normal at first. Your vision continues to improve over the next few weeks as your eye heals. Most people return to work and light activities within a few days, but complete healing can take several weeks.
You may see halos or glare around lights, especially at night. These effects usually decrease over time as your eyes adapt to the phakic IOL.
We prescribe antibiotic drops to prevent infection and anti-inflammatory drops to reduce swelling and discomfort. You will use these drops several times a day for a few weeks. It is very important to follow the exact schedule to help your eye heal properly and reduce the risk of complications.
- Wash your hands before putting in eye drops
- Do not let the dropper tip touch your eye or any surface
- Wait a few minutes between different types of drops if you use more than one
- Continue drops for the full course even if your eye feels fine
For the first week, avoid swimming, hot tubs, and getting water directly in your eye when you shower. Do not rub your eyes or do any heavy lifting or strenuous exercise. Wear protective eyewear if you play sports or work in dusty or dirty environments. Avoid eye makeup for at least one week and take care to keep soap and water out of the eye.
We usually recommend waiting at least two weeks before resuming activities like contact sports or vigorous workouts. Your surgeon will tailor clearance for contact sports or high-impact activities based on your healing.
Your first follow-up visit is usually the day after surgery. We check your vision, eye pressure, and the position of the phakic IOL. Additional visits occur at one week, one month, three months, and then yearly. Monitoring your eye pressure is especially important because phakic IOLs can sometimes cause it to rise. We also evaluate the lens vault and, for toric lenses, confirm axis alignment. If a toric lens rotates, we may reposition it.
- Day one: Check healing, position, and pressure
- One week: Assess vision improvement and inflammation
- One month: Confirm stable vision and normal pressure
- Three months and beyond: Long-term monitoring for complications
- Each visit: Document lens vault with slit-lamp or imaging
- Toric lenses: Verify axis alignment and stability
Most patients achieve stable, clear vision that lasts for many years. The phakic IOL stays in position and continues to correct your vision without needing adjustments. Long-term studies show that modern phakic IOLs are safe and effective when patients attend regular follow-up appointments. Toric lenses can occasionally rotate, causing astigmatism to return. Repositioning is usually straightforward if needed.
Your natural lens will still age over time, so you may eventually develop cataracts or presbyopia that requires reading glasses. If cataracts develop, we can remove the phakic IOL during cataract surgery and replace your natural lens with a cataract IOL. We recommend periodic follow-up, and in some cases endothelial cell count monitoring, based on lens type and surgeon preference.
Possible Complications and When to Get Urgent Care
Mild redness, light sensitivity, and a gritty feeling in your eye are common in the first few days. You may also notice glare, halos, or starbursts around lights, especially at night. These side effects typically improve as your eye heals.
Some patients experience dry eyes or mild fluctuations in vision during the first few weeks. Using lubricating eye drops and following your prescribed medication schedule can help manage these symptoms.
Phakic IOLs can sometimes interfere with the normal flow of fluid inside your eye, which can raise your eye pressure. High eye pressure can damage your optic nerve over time if it is not treated. We monitor your pressure at every follow-up visit to catch any increases early. Pupillary block is a specific form of pressure rise that can occur if fluid cannot pass from the back of the eye to the front. Central-flow lens designs and laser iridotomies are used to prevent this.
- Increased pressure can occur soon after surgery or develop gradually
- Most cases respond well to pressure-lowering eye drops
- Rarely, the phakic IOL may need to be repositioned or removed
- Regular monitoring is essential for early detection
Posterior chamber phakic IOLs sit very close to your natural lens. Over time, contact or close proximity can cause clouding of your natural lens, forming a cataract. The risk of cataract is higher if the phakic IOL is not sized correctly or if it touches your natural lens.
If a cataract develops, we can remove both the phakic IOL and your natural lens and replace them with a standard cataract lens. This procedure is safe and effective, and most patients still enjoy excellent vision afterward.
Although uncommon, serious complications can occur. These include infection inside the eye, damage to the corneal endothelial cells, and retinal detachment. Choosing an experienced surgeon and attending all follow-up visits reduces these risks significantly.
- Endophthalmitis, a severe infection that requires immediate treatment
- Progressive loss of corneal endothelial cells leading to corneal swelling
- Retinal detachment, more common in people with high nearsightedness
- Lens dislocation or movement from its correct position
- Pigment dispersion from iris chafing, which can raise eye pressure
- Uveitis-glaucoma-hyphema syndrome due to mechanical irritation
Call our office immediately if you experience sudden vision loss, severe eye pain, or a significant increase in redness. Flashes of light, new floaters, or a curtain or shadow in your vision can signal retinal problems. Persistent nausea or vomiting along with eye pain may indicate very high eye pressure. Severe headache with rainbow halos around lights and nausea can signal acute angle closure or pupillary block.
Prompt treatment of these symptoms can prevent permanent vision loss, so do not wait to contact us if you notice any of these warning signs.
Frequently Asked Questions
Removal is often possible if complications arise or your vision needs change. However, some changes such as corneal endothelial cell loss or early cataract may not fully reverse after removal.
Phakic IOLs are designed to be permanent and can remain in your eye for decades. However, life changes such as cataract development may require lens removal and replacement later in life.
Most patients achieve excellent distance vision without glasses. However, you may still need reading glasses once you reach your 40s due to presbyopia, the natural age-related loss of near focusing ability.
Small prescription changes are uncommon but can occur. If needed, we may enhance your vision with glasses, contact lenses, or in some cases, a laser vision correction touch-up procedure once your eyes are fully healed.
Most modern posterior chamber lenses with a central flow feature do not require a laser iridotomy. If you are receiving a lens design that does, we will perform it before surgery.
Alternatives include LASIK, PRK, SMILE, and refractive lens exchange. We will review the safest option for your eyes and prescription.
Getting Help for Phakic Intraocular Lenses (IOLs)
If you are considering phakic IOL surgery or have questions about whether you are a candidate, we encourage you to schedule a comprehensive eye exam and consultation with our eye doctor. Together, we can discuss your vision goals, review your eye health, and determine the best treatment option to help you see clearly.