The term “corrective eye surgery” covers several potential procedures. (Learn More) Some of these options are more popular than others, and some operations are cosmetic, like LASIK, and minor procedures with fast healing times. Other types of corrective eye surgery for refractive errors may mean more invasive options, including implants, but these help people with higher, more dangerous refractive errors. (Learn More)
If you have questions about which type of corrective eye operation is best for you, consult an optometrist or ophthalmologist. Keep reading to learn more about the options available, so you can ask informed questions. (Learn More)
What Is Corrective Eye Surgery?
Corrective eye surgery can refer to a range of procedures that correct errors in visual acuity — most often, refractive errors. A refractive error is a problem with vision caused by the shape of the eye, often due to a misshapen cornea, which prevents light from hitting the retina correctly, so the brain does not process a clear image of the world. These errors include:
- Myopia, the clinical term for nearsightedness, when objects that are far away appear blurry.
- Hyperopia, the medical term for farsightedness, when objects closer to the eyes are difficult to focus on.
- Presbyopia, a type of farsightedness caused by aging, typically impacting people who are 50 or older.
- Astigmatism, in which the eye is not spherical and the surface is warped, causing light to refract poorly through the lens.
Until the 1950s, the only way to correct refractive errors involved wearing glasses. While many people still choose to wear glasses, contact lenses became a popular alternative in the 1950s. Starting in the 1980s, surgical options using microkeratomes, or very small, mechanically operated blades, and lasers became increasingly popular options for correcting refractive errors.
At first, surgical options were used only to treat serious refractive errors since the procedures were fairly invasive, and healing took a long time. Now, thanks to advancements in laser technology, procedures are considered primarily cosmetic, and it only take a few days to heal most of the time. You can have corrective surgery for a minor refractive error like farsightedness, which takes up to 10 minutes per eye at most, and then be back at work the next day.
There are a few different choices for corrective eye surgery. The chosen procedure can make a difference in your post-surgical visual acuity, and one option may be better for you than others. Your optometrist or ophthalmologist can help you determine which is the best option for you. The information below can help you understand what the options are, so you know which procedures to talk about with your eye doctor.
Types of Corrective Eye Surgery Range From Laser-Guided to Implants
For the most part, surgeries applied to correct refractive errors are some form of cosmetic laser surgery similar to laser in-situ keratomileusis (LASIK).
- Traditional LASIK: When most people think of vision surgery, LASIK is the first type of procedure that comes to mind. The term LASIK has come to refer colloquially to several kinds of laser-based eye surgery procedures, but in truth, laser in-situ keratomileusis is a specific type of surgery, with several variations on LASIK. There are also other laser-based corrective eye surgeries that may work better for you. Traditional LASIK, like related procedures, is an outpatient surgery. You may have LASIK on one or both eyes, and each eye takes 5 to 10 minutes, depending on how long the setup needs to be. Before the procedure, you will receive eye drops to numb your eyes. You will then sit in a chair, and a device will be used to keep your eye open. You will be asked to look at a specific point while a microkeratome (a very small, machine-guided blade) opens a flap in your cornea so the laser can reach the lens of the eye through your pupil. The guided laser will then reshape your cornea, based on your glasses or contact lenses’ prescription, so light will refract clearly onto the retina and you will see more clearly. Then, the flap will be replaced over your eye, and you will receive a special contact lens over the flap to create a bandage.You will not be able to drive home, and your surgeon will likely tell you to rest your eyes for several hours after the procedure. Many people experience improvements in their visual acuity by the evening of their surgery and often return to work the next day. If you have a physically active job or a job that requires use of heavy machinery, you should consider taking several days off until your ophthalmologist tells you that the corneal flap has healed. Although many people achieve near-perfect vision, the estimated outcome of any LASIK procedure is 20/40 vision or better. Essentially, you should be able to drive safely and read clearly without glasses or contact lenses, although you may not be able to see completely perfectly. There are side effects associated with LASIK. These typically clear up within six months after the procedure, but in rare cases, become permanent. Side effects include risks like:
- Dry eye.
- Hazy or blurry vision.
- Haloes or glares around lights.
- Trouble with night vision or driving at night.
- Itchy feeling or scratchiness, like you have something in your eye.
- Light sensitivity.
- Discomfort or pain.
- Difficulty with flap healing.
The U.S. Food and Drug Administration (FDA), which oversees the safety of LASIK devices and procedures, conducted a study in 2017 and found that newer devices, better training, and improved steps in the procedure itself have all reduced the risk of side effects after LASIK.
- Bladeless LASIK: Like traditional LASIK, bladeless LASIK takes less than 10 minutes per eye to perform; however, the corneal flap is created with a second laser device rather than a bladed microkeratome. There are differing opinions among eye surgeons about which procedure is better, and different eyes may have different reactions.In some instances, the laser used to create the flap may be a second device, so you may have to be moved between rooms for the procedure, which means that the operation takes longer. Overall, this is an inconvenience, but it does not affect outcomes or healing. Healing time and visual acuity are both slightly improved for most people when all the lasers used in wavefront LASIK are on the same device, and the surgeon has been thoroughly trained on this approach.
- Wavefront LASIK: This form of LASIK uses wavefront technology to map the full surface and structure of your cornea and lens before your operation. Rather than use your glasses prescription to guide the laser that will reshape your cornea, the wavefront map, which looks like a topographical map, is used to more precisely correct your vision by removing inconsistencies on the surface of the cornea. Vision typically is improved slightly more than in traditional LASIK, errors other than refractive errors may be corrected for, and a handful of patients report developing better than 20/20 vision after the operation.
- Epi-LASIK: Again, this is essentially the LASIK procedure, but with a specific blade called an epi-keratome that is used to create the thinnest possible flap of corneal tissue to reduce healing time and improve healing outcomes.
- Laser epithelial keratomileusis (LASEK): This procedure was developed shortly after LASIK and is similar in many respects. The main difference is that the epithelium over the eye is detached using an alcohol solution of between 18 and 20 percent. Then, the epithelium is removed as a flap, which is folded over during the laser procedure. It is replaced afterward with special focus to achieve correct alignment.
- Photorefractive keratotomy (PRK):
Much like LASIK, you can have PRK on one or both eyes, and the surgery does not last very long — typically, 30 minutes or less. You will receive numbing eye drops, your eyelids will be held open by a specific device, and you will be asked to stare at a dot during the procedure. Unlike LASIK, your surgeon will remove the outer layer of cornea completely rather than creating a flap that will be put back in place. This may involve an alcohol solution, special brush, or microkeratome, depending on the device and the surgeon’s training. Then, a laser will reshape your cornea.Like with LASIK, you will need help getting home. Unlike with LASIK, your vision will take three to five days, rather than several hours, to improve. You will need to take time off work or school to recover completely.Many side effects, like dry eyes, halos or glares around lights, and night vision issues are similar to those of LASIK. With PRK, there is a slightly higher risk of corneal infection because of how the cornea is managed during the procedure, and there is also a risk of “corneal haze,” or a type of scarring as the cornea heals over the pupil, which may impact vision in the worst-case scenario.There are still people who are not good candidates for PRK, such as those with the following conditions:
- Unstable or greatly changing refractive errors
- Skin, blood vessel, autoimmune, or other conditions that would affect the healing process
- Corneal abrasions or disease
- Pregnant or nursing
- Other chronic eye infections
Like LASIK, the risk of side effects is minimal. About 9 out of 10 people who undergo PRK get 20/40 vision or better.
- Radial keratotomy (RK): This procedure was developed before PRK, and it does not use lasers at all. While it is not the first or best corrective eye surgery option anymore, and it is not likely to be recommended, it may be an option for some people who will not work well with PRK or LASIK.RK works only for people with myopia. Small incisions are made in the surface of the eye to flatten it, along with the lens, to change how light is refracted through the eye.Fluctuating vision, rapid regression, glares around lights, light sensitivity, and other problems were reported among many patients who underwent RK. The operation tended to work better for people with low myopia rather than higher rates of myopia.
- Conductive keratoplasty (CK): Unlike other types of microkeratome and laser-based surgery, CK is a good option to treat changing refractive errors in people over the age of 40. A probe uses thermal or radio frequency energy to reshape your cornea rather than a laser. The heat increases the curvature of the cornea, shrinking the peripheral areas to tighten them, which improves how light is focused on the retina. This operation may be used to achieve monovision, in which one eye with presbyopia has perfect vision, and the other eye retains its refractive error, but you can still see distances clearly. This is also not a permanent solution to presbyopia, as the eye will continue to change with age.
Laser and microkeratome surgeries like those listed above are great options for people with standard refractive errors, especially astigmatism, myopia, and hyperopia. People who have presbyopia may benefit from some of these procedures, but because their corneas will continue to change with age and lead to increased farsightedness, not every option above works well.
If you are interested in a laser or microkeratome surgical procedure to correct your vision, you must:
- Be at least 18 years old for myopia and hyperopia, and at least 21 years old for astigmatism.
- Have a refractive error that is stable or has changed very little over the past year.
- Have nearsightedness less than -14 diopters. More than that and a lens replacement is a better option
- Have astigmatism of less than 5 diopters.
- Have hyperopia of less than +6 diopters.
- Not have additional eye problems like glaucoma, cataracts, keratitis, corneal scarring, or other injuries or infections.
- Not have additional medical problems like diabetes, lupus, autoimmune conditions like rheumatoid arthritis, immunosuppressant conditions like HIV/AIDS, or heart or vascular conditions.
- Not take certain medications that disqualify you from cosmetic corrective vision surgeries.
- Not be pregnant or breastfeeding.
For those who do not qualify for cosmetic eye surgeries due to serious vision problems, there are surgical procedures to correct more serious refractive errors, which involve implants to replace corneal lenses that are too misshapen or damaged.
- Phakic intraocular lens (IOL) implants: These are lens replacements for people who have such a high degree of refractive error that less invasive options will not correct the problem in the existing, biological lens. It is like an implantable contact lens, going over the existing lens internally to reshape the eye. During the procedure, your surgeon will determine if it is better to put the phakic lens in front of or behind your biological lens.
- Presbyopic refractive lens exchange (PRELEX) or clear lens extraction: Like the phakic IOL implants, these artificial lenses are implanted in your eye to permanently improve your vision if your biological lens cannot be treated with cosmetic procedures to improve your refractive error. Unlike phakic IOL, PRELEX replaces your existing lens, which is removed first. RLE or PRELEX works for people who have refractive errors and early stage cataracts to replace lenses damaged by cataracts or for some people with extensive hyperopia, for whom LASIK is not recommended.
What Type of Corrective Eye Surgery Is for You?
If you struggle with a vision problem caused by a refractive error or an issue with the lens of your eye, you may qualify for some type of corrective eye surgery. LASIK and related procedures are typically considered cosmetic because you can continue wearing glasses or contact lenses to achieve 20/40 or better vision instead of undergoing a surgical procedure. This means that many insurance companies will not cover the cost of LASIK, PRK, or similar surgeries, or they will not cover much of the cost. Increasingly, as LASIK becomes more affordable and widespread, more insurance companies are providing options to manage your vision with this cosmetic option.
If you have a more serious refractive error requiring implants, your insurance is more likely to cover these procedures to prevent further visual degradation. The type of procedure that works best for you ultimately involves a conversation between you and your ophthalmologist. With the information above, you can ask more specific questions about the types of procedures you are interested in and get referrals for the best type of treatment.
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LASIK – FAQs (Frequently Asked Questions). (July 11, 2018). U.S. Food and Drug Administration (FDA). Alternative Refractive Surgery Procedures. (September 27, 2017). American Academy of Ophthalmology (AAO).
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What is Photorefractive Keratectomy (PRK)? (September 27, 2017). American Academy of Ophthalmology (AAO).