Laser Eye Surgery: ReLEx SMILE vs LASIK vs PRK

The three main types of modern Laser Eye Surgery are PRK, LASIK and ReLEx SMILE. All three treatments are quite similar, in that they’re all performed on the cornea; however, there are several important differences.

Sit back and watch as expert laser eye surgeon Mr. Glenn Carp sheds a little light on what these differences are how each of the Laser Eye Surgery techniques alter the shape of the eye.

ReLEx (refractive lenticule extraction) SMILE (small incision lenticule extraction)

ReLEx SMILE is the latest generation of Laser Eye Surgery, co-invented by Prof Reinstein, here at London Vision Clinic.

The procedure — known as SMILE for short – is totally ‘flap-less’, and involves a tiny keyhole incision being made in the cornea. The surgeon is able to remove a precise amount of tissue through this incision.

Because there are no moving parts, the healing time for SMILE is even quicker than that of conventional LASIK, the common temporary side effects of Laser Eye Surgery (including dry eye and night vision disturbance) are minimised, and the procedure is suitable for even those patients with very high prescriptions, drier eyes, and thinner corneas.

LASIK Laser Eye Surgery

Properly termed Laser-assisted in situ keratomileusis, LASIK is by far the most common Laser Eye Surgery procedure.

The key difference between LASIK and PRK & LASEK is that, instead of removing the surface layer of the eye, a ultra-thin flap is created to allow the laser treatment to be applied, after which the flap is simply replaced.

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By returning the flap to its original position in this way, it’s only the edge of the flap which needs to heal. The recovery time is, therefore, a fraction of the recovery time from PRK or LASEK — the vast majority of LASIK patients are ready to go back to work within 24 hours of having Laser Eye Surgery.

PRK (photorefractive keratectomy) and LASEK (laser assisted sub-epithelial keratectomy)

In PRK Laser Eye Surgery, the surface layer of the eye is removed (this is the epithelium, which is naturally replaced by the eye every 7-14 days).

The more permanent layer beneath the epithelium is then reshaped, correctly readjusting the vision. A contact lens is then applied as a bandage, allowing the surface layer to heal naturally.

In LASEK Laser Eye Surgery, similar to PRK, the surface layer of the eye is removed. Instead of discarding the layer as with PRK, the layer is moved aside. The laser eye treatment is then carried out in the same way, before the retained surface layer is draped back over the eye. A contact lens bandage is then applied to allow the eye to heal.

To find out if you are suitable for PRK, LASIK or ReLEx SMILE Laser Eye Surgery, leaves us a comment or chat with a member of our friendly team.

What’s the difference between PRK, LASIK And ReLEx SMILE Laser Eye Surgery?

  1. Jeff Onad 29/01/2015 at 12:40

    Good morning, I am doing some research to find the best eye surgeon, clinic and technic. I have a -7D both eyes , negligible astigmatism (thin cornea at 500um)
    I appreciate more analysis need to be made by a professional on pachymetry and topography.
    I am impressed by credentials and reviews on Pr Reinstein and your clinic. I also came across one of your competitor claiming unbelievable acuity results up to -8D (100% 20/20 udva or better which seems too good to be true). They claim their success is (aside from surely experienced surgeon) mostly driven by use of the higher frequency Femto LDV from Ziemer which ensure very neater and smoother flap (i think they use eyeQ as excimer).
    I understand your technology is based on visumax + MEL90 currently. I appreciate a begginner pianist on a Steinway will not play better than a Rachmaninov on a Casio keyboard. However I would like to have your view on the potential results of your platform Vs Z-lasik for relatively standard high myopia patient.? Should I beware of clinic claiming 100% 20/20 thanks to z-lasik technology? Is there a type of SE refraction, or refractive aberration, patient specific factors, for which your platform is superior or weaker vs others?

    • London Vision Clinic 29/01/2015 at 17:36

      Hi Jeff. Thanks for getting in touch. As you said, the technology we favour at London Vision Clinic includes the Visumax and MEL 90, which we believe to be two of the best lasers available. The dynamics of the flap created by the Visumax are of the highest level of accuracy with the best possible profile. Likewise the MEL 90 delivers the most accurate, auto-stabilised calibrated laser energy available (which is critical for ultimate accuracy, as fluctuations in laser energy can cause inaccuracies in the final outcome); it also offers highly customised ablation.
      Bearing in mind that, of course, we would have to see you in person and examine your eyes in order to give you a personalised recommendation, our results for prescriptions around -7.00D are extremely good (they can be found here: We would be unable to comment with authority on the results you may have seen advertised elsewhere. Please don’t hesitate to call us on 020 7224 1005 if you have any further questions, or email

  2. meka 24/04/2015 at 15:07

    I recently had a consultation re Relex Smile and was told that as my precription is -11.75 in my left eye and -10.5 in my right I would still need glasses abd lenses. This news was a huge disapointment. I can only be corrected to 1.75 left and .5 to the right eye. I have also read some disturbing horror stories about floaters, hazy night vision, halos and drooping eyelids. Now I am left wondering if I should risk what little eyesight I have left for months of pain

    • Bethany Kingsley 18/05/2016 at 15:34

      Hi Meka,

      Did you have a consultation here? We would certainly want to make sure that it was the right thing for you and ensure you are clear on all of the risks. It is unlikely that you would have pain following surgery. Please let us know if we can clarify anything for you by calling 0207 224 1005 or emailing


      London Vision Clinic

  3. meenaxi 19/08/2015 at 02:02

    hello thanks for this information .

  4. Priya Joshi 05/06/2016 at 10:54

    I have mild dry eyes. I am unable to wear contact lenses anymore. Am i a good candidate for relex smile ? I am going to be a doctor myself so i am worried about any potential side effects.

    • Bethany Kingsley 06/06/2016 at 08:56

      Hi Priya,

      Thank you for your comment. ReLEx SMILE can be more suitable for a patient who suffers from previous dry eye, yes. However, to fully determine your suitability and ascertain the best option for your eye we would have to see you for a thorough suitability consultation and eye health exam. At this appointment we will also go through all of the potential side effects with you. Please give us a call on 0207 224 1005 if you have any further questions.
      London Vision Clinic

  5. Jamie Waldron 13/06/2016 at 20:08

    I had laser eye surgery 8 years ago at the age of 40, my sight is now +.75 in both eyes and I require reading glasses. Is it possible have a second treatment and is it advisable?
    Regards Jamie.

    • Bethany Kingsley 14/06/2016 at 06:59

      Hi Jamie,
      It is possible to have further retreatment, however, the process is slightly more complicated when taking on another surgeon’s work. Professor Reinstein specialises in Therapeutic cases and you would need to have a thorough consultation to determine if treatment would be the best option. Please contact the clinic on 0207 224 1005 for more information.

      London Vision Clinic

  6. Hamsa 29/10/2016 at 13:57

    HI, I’m 26 years old with mild myopia of -1.50 D in my right eye and -2.50 D in my left eye and have astigmatism of 0.5 and my corneal thickness of 500 microns Am I suitable for RELEX smile??

    • Bethany Kingsley 30/10/2016 at 10:03

      Hi Hamsa,
      I am afraid we would need to assess your eyes through a thorough examination to determine if you were suitable for treatment and what procedure would be performed. Please call the clinic for more information in regards to your suitability and information regarding the ReLEx SMILE procedure.
      London Vision Clinic

  7. Naveen 18/12/2016 at 13:34

    My glass numbers are -5.00 approx in both eyes along with cylindrical vision. Would like to know whether I should go for Lasik or Smile. kindly let me know pros and cons of both.

    • Bethany Kingsley 19/12/2016 at 10:05

      Hi Naveen,
      I am afriad that we cannot answer that question based on the information you have given. You would have to have a full comprehensive consultation and then the surgeon can make an informed decision as to the best procedure for you. It is based on many different factors. If you seek treatment at a specialist clinic they will advise what is the best option for you and explain the pros and cons for all treatments available to you.
      London Vision Clinic

  8. muge erdiniz 11/04/2017 at 14:37

    Hi, I had a RELEX Smile eye surgery before 1 years ago. My eyes were approx. -5.0. Now my left and right eye both -1.5. So I talked with y doc and he can do PRK again. But the main problem is; Is this normal after Smile eye surgery? I am very dissapointed. thanks.

    • Bethany Kingsley 18/04/2017 at 12:42

      Hi Muge,

      Unfortunately, we cannot give you any clinical information without thoroughly assessing your eyes and your previous medical records. Please contact the clinic on 020 7224 1005 for more information.
      London Vision Clinic

  9. Zwain 22/01/2018 at 19:46

    Hi there

    I had lasik 4 months ago, and still having problems with my vision especially the very near vision and far vision.

    is it possible to have enhacement surgery?

    I live far away from London, so if the decision was to have surgery, will it be possible in the same week?

    Kind Regards

    • Bethany Kingsley 23/01/2018 at 15:24

      Hi Zwain. Enhancements are often possible, however we are unable to comment without seeing you.
      We would need you to come in for a full eye health examination to see what is possible and if we could improve your vision further.
      To find out more, please call us on 020 7224 1005.
      Thanks, LoVC

  10. Tahira Malik 21/02/2018 at 17:27

    Hello. I have very dry eyes and have been using HycoSan Dual for six months. I can’t wear contact lenses anymore. My number is -6 and -5. Am I good candidate for SMILE? I live in Pakistan and will have to make a decision to come to you based on certain initial assessment. Thanks

    • Bethany Kingsley 26/02/2018 at 12:02

      Hi Tahira,

      Thanks for your comment. You would need to come in for full eye health assessment, to determine various factor including your dry eye. Your suitability will be determined at this appointment, and which procedure is most appropriate for you.

      Many Thanks,
      London Vision Clinic

  11. Si 14/04/2018 at 15:54

    Does pigment deposition syndrome prohibit laser eye surgery

    • Chloe Lay 04/05/2018 at 09:15

      Hi Si.
      No, laser eye surgery can still be performed. With pigment dispersion syndrome you are at a higher risk of going on to develop glaucoma regardless of if you have laser eye surgery or not. You would be referred to see a glaucoma specialist following an assessment. You can call us on 020 7224 1005. Kind Regards, London Vision Clinic

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