Smile Eye Surgery

    Last updated date: 03-Mar-2023

    Originally Written in English

    SMILE Eye Surgery

    SMILE Eye Surgery


    Refractive errors are a category of vision problem that makes seeing clearly difficult. They occur when the shape of your eye prevents light from properly concentrating on your retina (a light-sensitive layer of tissue in the back of your eye).

    The most prevalent form of visual impairment is refractive error. Over 150 million Americans have refractive error, yet many are unaware that they might see better. That is why regular eye exams are so vital. Your eye doctor can prescribe eyeglasses or contact lenses to help you see properly if you have a refractive problem.

    There are 4 common types of refractive errors:

    • Nearsightedness (myopia) makes far-away objects look blurry
    • Farsightedness (hyperopia) makes nearby objects look blurry
    • Astigmatism can make far-away and nearby objects look blurry or distorted
    • Presbyopia makes it hard for middle-aged and older adults to see things up close

    Refractive errors can be caused by:

    • Eyeball measurement (when the eyeball grows too long or too short)
    • Corneal shape abnormalities (the clear outer layer of the eye)
    • Aging of the lens (an inner part of the eye that is normally clear and helps the eye focus)


    What is SMILE Eye Surgery?

    SMILE Eye Surgery

    SMILE is a form eye surgery used to treat refractive problems. Myopia (nearsightedness), hypermetropia (farsightedness), astigmatism (blurred vision at all distances), and presbyopia (an inability to focus your eyes up close) are the four forms of refractive errors.

    Your eyesight is dependent on your cornea and lens concentrating a clear image of the world before you onto your retina. This necessitates the refraction (bending) of light rays in order to form a sharp image on your retina. The cornea and lens are in charge of refraction. Changes in the shape of the cornea cause the picture on the retina to become unfocused, resulting in hazy vision.

    It is difficult to live with astigmatism, myopia, cataracts, and other severe eye disorders. Laser eye surgery is not a novel notion for improving eyesight and quality of life. It has been around for decades and has evolved significantly over that period. Many people who suffer eye problems have wondered if a procedure may address their corneal problems.

    Rather than wondering, understanding about the precise alternatives available will assist you in taking the critical first step toward therapy that allows you to see properly. Laser treatments are frequently the most effective. Laser surgery is classified into three types. Laser surgery is classified into three types. Photorefractive keratectomy (PRK), LASIK (Laser-Assisted In-Situ Keratomileusis), and SMILE laser eye surgery are among them (small incision lenticule extraction).

    The SMILE (small incision lenticule extraction) surgical treatment reshapes your cornea. This precisely concentrates light on your retina, providing you with clear eyesight. SMILE (laser-assisted in situ keratomileusis) is a relatively recent alternative to the well-established LASIK (laser-assisted in situ keratomileusis) surgery.

    The curvature of your cornea is altered with SMILE surgery. This returns refraction to normal, restoring keen vision. It eliminates the need for spectacles or contact lenses. You might be able to see without them. SMILE is a newer technology. It was authorized in 2016 for myopia correction and in 2018 for astigmatism correction.


    Who are the candidates for SMILE Eye Surgery?

    SMILE Eye Surgery

    SMILE, like all surgical treatments, has several prerequisites. These make it safer for you and boost your chances of success:

    • You should be at least 22 years old.
    • Your vision should be stable. Your eye prescription should not have changed in the past year.
    • Your eyes and corneas should be healthy.
    • Your myopia should be between −1 and −10.
    • Your astigmatism should be less than 3 diopters.

    SMILE laser eye surgery is more accessible than other methods such as LASIK and LASEK. If you've been informed you're not a candidate for another type of laser eye surgery, SMILE may be a viable option.

    For example, if any of the following apply to you, you may be ineligible for LASEK or LASIK therapy, although SMILE eye surgery may still be an option:

    • You have a thinner than average cornea
    • You have an intolerance to contact lenses
    • You have mild to moderate dry eyes

    SMILE surgery can improve your eyesight and eliminate the need for glasses or contact lenses. However, this treatment is not suitable for everyone. Some medical issues may preclude you from having this surgery:

    • Very thin corneas
    • Irregular astigmatism
    • Scars on the cornea
    • Progressive ectasia (thinning of the cornea)
    • Changing (unstable) refraction
    • Cataracts in one or both eyes
    • Glaucoma
    • Diabetes, uncontrolled
    • Earlier eye surgery or disease
    • Pregnancy or breastfeeding


    How is SMILE Eye Surgery is done?

    SMILE Eye Surgery Procedure

    Patient preparation:

    Your ophthalmologist will do a thorough eye examination prior to surgery. They'll want to make sure you don't have any eye issues, particularly with the cornea. Some eye problems might interfere with or worsen following SMILE surgery. They'll check to see if your eyesight has altered in the last year. It must also be within the limitations of what SMILE can fix.

    Your ophthalmologist will also measure and assess the thickness of your cornea. These measurements will then be sent into the computer that controls the SMILE laser.



    SMILE is often performed as an outpatient treatment. You will not be required to spend the night in the hospital. It is a computer-assisted treatment that typically takes around 20 minutes. Both of your eyes are treated at the same time.

    Local anesthetic is used for the surgery. To numb your eyes, medicine drops are inserted. In the cornea, a tiny lens-shaped disc is carved with a femtosecond laser. This disc is retrieved by a modest 2-to-3-millimeter incision. The femtosecond laser is also used to make this incision. This method reshapes the cornea to precisely reverse the eye's refractive defect.

    SMILE, which stands for Small Incision Lenticule Extraction, is a procedure that employs innovative technology created by Carl Zeiss Meditec, Inc. to reshape your cornea in a manner similar to LASIK but with a considerably smaller incision. SMILE works by sculpting a small, lens-shaped tissue in the eye and making a minuscule incision on the cornea surface using a femtosecond laser.

    The surgeon then extracts the tissue, called as a lenticule, via the incision, altering the cornea and therefore curing nearsightedness. The patient will heal normally and recover in one to two days after the lenticule is removed. The surgery is quick and painless, and ophthalmologists all around the world recommend it.

    It is the third generation of refractive surgery, after LASIK eye surgery in terms of technology. This is due to the fact that it is effectively a one-step laser technique that produces remarkable results with less invasive surgery.


    What are the benefits of SMILE Eye Surgery?

    benefits of SMILE Eye Surgery

    More people are accepted for this type of treatment – Because SMILE is a minimally invasive kind of laser eye surgery, it is appropriate for a wider range of patients than LASIK and LASEK. This is a significant advantage for people who have been informed they cannot undergo other forms of surgery.

    No chance of flap complications – The fact that no flap is generated during the SMILE operation distinguishes it from other procedures such as LASIK. This eliminates the danger of issues like as the flap folding or migrating, and it also makes the eye more comfortable following the treatment.

    Quick procedure – SMILE, like other laser eye surgery treatments, is extremely quick. The overall treatment time is often between 20 and 30 minutes.

    Speedy recovery – Because no flap is generated across the cornea, patients should expect to recover faster with SMILE eye surgery and feel less discomfort than with other procedures such as LASIK. Unlike LASEK surgery, no bandage lenses are normally required, however physicians may advise you to wear them overnight as a precaution in rare circumstances.

    Fast results – According to trials conducted in the UK, Germany, France, and Denmark, vision improves by 80% during the first few hours of SMILE eye surgery and reaches full improvement within a few weeks. In comparison, LASIK often produces results within 24 hours, although LASEK might take several days.


    What are the possible side effects of SMILE Eye Surgery?

    side effects of SMILE Eye Surgery

    According to research, after the SMILE treatment, eyesight is normally 80% improved within a few hours and 100% better within a few weeks. One thing to keep in mind is that, while recovery is swift, there is a potential that your eyesight will be little impaired following the procedure.

    Aftercare plans include an appointment the day after surgery and then follow-up checkups at regular intervals for up to 12 months. Aftercare consultations are a time for you to express any concerns you may have, as well as for your surgeon to check on your progress and determine whether more treatment is necessary.

    When weighing vision correction surgery choices, it's critical to examine the risks vs advantages of each technique. Here are some of the most prevalent dangers associated with SMILE procedures:


    Debris left behind:

    When you realize that SMILE includes separating and removing tissue from the mid-cornea layer, you can see how inadequate tissue removal can be a distinct difficulty. A corneal abrasion, adhesions, and incisional tears might result from the presence of leftover corneal debris. These will need the use of a bandage contact lens and, at worst, protracted healing, and, at best, discomfort and inflammation.

    Debris can be flushed out using non-invasive procedures if detected early. In severe circumstances, removing the debris may necessitate a second surgical treatment. Debris symptoms are often transient, but they might prolong and complicate healing.



    While inflammation is a typical side effect of any invasive operation, it can complicate and prolong healing in extreme circumstances. Because SMILE removes more corneal tissue than LASIK, there is a higher risk of post-op inflammation. SMILE patients must be always watchful for discomfort or vision issues. To avoid further escalation, patients should immediately notify their eye surgeon of these symptoms.


    Clouded Vision:

    Because SMILE is intended to address nearsightedness, it is more likely to create foggy vision problems. In fact, individuals who have SMILE surgery report more concerns with hazy vision and light sensitivity one month after surgery than those who have LASIK.


    Dry Eyes:

    Dry eyes are the most prevalent adverse effect experienced by all laser surgery patients, and SMILE patients are no exception. SMILE ads claim that their patients have less post-op dry eye than LASIK patients. This is due to the SMILE method disrupting fewer corneal nerves. This is especially concerning for persons who already have dry eyes.

    SMILE appears to have a lower incidence of dry eye complaints as compared to traditional LASIK surgery. Today's 5th-generation LASIK, known as EagleVision, uses a novel surgical method to reduce post-op dry eye problems.


    Over or Under Vision Correction:

    Over or under correction can occur if too much or too little corneal tissue is removed during a SMILE operation. As a result, your eyesight issues will be worse than before surgery, prompting a retreatment. Overcorrection may cause your nearsightedness to be replaced with farsightedness.

    Up to three months after surgery, a large number of SMILE patients experience reduced visual acuity. Unfortunately, they will have to wait until their eyesight has stabilized before undergoing enhancement surgery to fine-tune their vision correction. It's vital to know that once you've had SMILE, you can't have it again. To address any mis-correction concerns, you will need to have PRK or LASIK surgery.


    Corneal weakening and tensile strength loss:

    A 2016 meta-analysis of 11 clinical studies comparing SMILE and LASIK results discovered that corneal sensitivity was higher in SMILE patients than in LASIK patients at one week and six months post-op. A biomechanical research that tested the tensile strength of post-op corneas discovered that SMILE corneas lost 40% more tensile strength after surgery than LASIK corneas.

    Corneal warping (also known as ectasia) can cause a variety of visual issues and difficulties that can only be repaired with glasses or contact lenses. In extreme circumstances, a corneal transplant may be required.


    SMILE vs LASIK Eye Surgery

    LASIK Eye Surgery

    One of the simplest ways to explain small incision lenticule extraction (SMILE) laser vision correction is to relate it to Keratomileusis (LASIK) or refractive therapies. The latter has been a common surgical laser procedure for decades, and many people are familiar with it. In essence, the two techniques approach optical therapy in quite different ways. Keratomileusis begins with a laser beam creating a corneal flap. This flap is effectively supported by a tissue hinge. The surgeon will then draw the tissue flap back. The lens is then reshaped using a separate instrument (an excimer laser).

    However, with the SMILE technique, no LASIK flap is formed. Instead, the fast-pulsing femtosecond laser light is employed to construct tissue within the cornea. The same stimulated light amplification is then used to make a tiny incision in the center of the body to remove the built-up tissue. The ultimate result is a reshaped cornea without a hinged flap, a considerably smaller incision, less laser exposure, and overall less invasion than with LASIK.


    Dry eyes:

    In comparison to LASIK and other refractive treatments, SMILE patients have reported considerably fewer and less severe episodes of dry eyes after the laser treatment. There are several plausible explanations for this. One advantage of not having a corneal flap is that the eyes are less irritated overall. Another difference is that the SMILE incision is substantially smaller. Regardless, it appears evident to medical research that minimizing the invasiveness of therapy may also lessen side effects, and this is one way it presents.


    No corneal flap:

    The use of a femtosecond laser eliminates the need for a LASIK flap, which is a significant benefit. The significantly bigger cut required to create the peeling layer is a cause of significant inflammation, irritation, and complication that can arise after the Keratomileusis excimer laser treatment is completed. By eliminating the cornea flap stage from the SMILE laser process, all of the negative side effects associated with the approach are eliminated. This is not to say that this treatment is without risks, but the simplified SMILE procedure reduces the range of vision and other complications that might arise.



    The lack of a LASIK hinge alters the nature of incision lenticule extraction (SMILE) as a treatment option for cornea-related visual issues like as myopia. Finally, the femtosecond laser causes this refractive eye surgery to be more specialized than Keratomileusis (as opposed to the excimer laser). This is both a benefit and a disadvantage.

    The approach targets a restricted spectrum of vision disorders, but the SMILE operation fixes those problems to a greater extent than Keratomileusis can, and generally with superior outcomes. This distinction is ultimately what allows surgeons and patients to judge which procedure is best for each situation. Sometimes specialization is advantageous; other times, it is detrimental (which will be discussed further in a moment).


    Single session application:

    Keratomileusis (LASIK) operations can be completed fast, however lenticule extraction (SMILE) is a one-session process. There is only one cutting instrument required. By eliminating the excimer laser from the process, the operation is simplified, which reduces risks and complications in the long term.


    Zeiss technology:

    Advanced optical technology is used in lenticule extraction (SMILE). The technologies in question generate exceedingly rapid pulses. This improves the operation's accuracy and control.

    A femto-second is a quadrillionth of a second to put this into perspective. That's tough to put into context, but here are some tries. Light is the quickest object in the world, yet it can only travel around 30 centimeters between these tool's pulses. Light may circle the globe seven times in a single second. Here's another angle to consider. The operation takes about 8 seconds. This equates to 8,000,000,000,000,000 femtosecond pulses.

    These extremely quick laser pulses enable the surgeon to make extraordinarily minute alterations to the SMILE procedure, allowing them to better treat eye abnormalities. This is a major reason why lenticule extraction (SMILE) can treat more advanced nearsightedness than other optical methods such as LASIK and PRK.


    What is the best option for me?


    This is a question that is best answered after a thorough consultation with an ophthalmologist, however there are a few aspects to consider. Because of its less intrusive technology, SMILE may be the best option for nearsighted people. It's also the most sophisticated treatment, therefore the results may be somewhat better.

    Because it tackles nearsightedness, farsightedness, and astigmatism, LASIK gives greater flexibility; nevertheless, if your corneal tissue is too thin, you may require another treatment. If this is the case, PRK may be the best solution for you. It is capable of addressing all visual disorders, similar to LASIK, but has a significantly longer recovery period. However, only a thorough eye exam with an ophthalmologist can determine which operation is best for you.


    How much does SMILE Eye Surgery cost?

    SMILE Eye Surgery cost

    Any surgical choice should be reviewed with a doctor, and talks regarding managing visual problems should include your ophthalmologist and/or surgeon. Have the talk if you believe you are a suitable candidate for SMILE.

    Most refractive eye physicians in the United States charge around the same fee for SMILE eye surgery as they do for all-laser LASIK — around $2,000 to $3,000 per eye.

    The following factors contribute to the fee surgeons charge for SMILE:

    • The surgeon's experience
    • The practice location
    • Whether follow-up exams and enhancements (if needed) are included

    When it comes to SMILE laser eye surgery cost versus risk, the only realistic comparison is to compare lenticule extraction (SMILE) to alternative therapies. The cost of other optical operations, including as LASIK and PRK, is comparable. You will not pay extra for this method, and it is frequently the most effective way to address nearsightedness. It appears to be a simple decision because it is substantially less invasive than other corneal operations.

    Having said that, there is a strong probability that SMILE will prove to be the best cost vs risk choice for many patients, even surpassing LASIK. The short procedural time, recuperation time, and total risk are difficult to beat, and recent developments have resulted in an excellent success rate for this approach. In one research, 88 percent of patients no longer required corrective glasses following the procedure.



    laser vision correction

    The most recent innovation in laser vision correction is Small Incision Lenticule Extraction (SMILE) laser eye surgery. SMILE is a minimally invasive surgery that produces excellent results in correcting myopia (nearsightedness). Aside from myopia, it may also be used to correct moderate astigmatism up to 5 diopters. SMILE is also known as Refractive Lenticule Extraction.

    If you are nearsighted – with or without astigmatism – you might benefit from SMILE laser vision correction. The next step is to undergo a full eye exam and visit with a refractive surgeon for laser vision correction.