What’s the Difference Between LASIK, SMILE and LASEK?

By Aris Konstantopolous
Difference between LASIK, LASEK and SMILE

Laser eye surgery, or laser vision correction, is a procedure in which laser is used to reshape the front surface of the cornea of your eyes, so that you can focus and see better. The cornea is the clear window-like structure at the front of the eye. 

Laser surgery can correct short-sightedness (myopia), long-sightedness (hyperopia) and astigmatism. Almost anyone who is over 18 years old is likely to be suitable for treatment, depending on how high the prescription is, the thickness of the cornea and the shape of the cornea. In addition, your eye prescription must have remained stable for 2 to 3 years. 

Broadly, there are three types of laser eye surgery; LASIK, advanced surface ablation (also known as LASEK) and SMILE. All three procedures have very similar outcomes but significant differences in how they are performed and the recovery period. 

Benefits of laser eye surgery

Laser eye surgery can improve your vision, most usually to driving standards within 24 hours. The quality of vision often exceeds that achieved with spectacles or contact lenses, particularly for higher prescriptions and astigmatism. 

Laser vision correction can provide you with freedom from glasses and contact lenses, allowing you to enjoy your active lifestyle without the hassle of spectacles and the risks of contact lens wear. The long-term risks of contact lens-associated infection, dry eye, and intolerance can be avoided permanently. You can wake with clear vision and enjoy the outdoors with your new designer sunglasses. 

What is LASIK?

LASIK is the most widely known laser vision correction procedure. It has been performed for over 30 years with over 40 million procedures worldwide. Often the terms LASIK and laser eye surgery are used synonymously. LASIK involves the use of excimer laser to reshape the cornea and match its refractive power to your prescription.  This is preceded by the creation of a corneal flap, a thin superficial layer of tissue; nowadays this is created with the use of a femtosecond laser, allowing great precision and safety.

What is LASEK or Advanced surface ablation (ASA)?

LASEK or ASA is very similar to LASIK. It’s use in the form of PRK predates that of LASIK. The principles are very similar to LASIK, involving the use of excimer laser to change the refractive power of the cornea. Prior to this the most superficial layer of the cornea, the epithelium, is removed. This is achieved either with the use of a weak alcohol solution that loosens the epithelium or the excimer laser. The epithelium then heals over the 2-3 days following the procedure. 

What is SMILE?

ReLEx SMILE (small incision lenticule extraction) is a keyhole laser vision correction procedure. It is a well-established refractive procedure that represents one of the latest developments in laser vision correction. Four million procedures have been performed over the past 10 years. It involves the creation and removal of a lenticule of tissue from within the cornea with the use of a femtosecond laser. This is minimally invasive as it is performed through a small 3 mm incision and opening of the cornea. Due to its keyhole nature it does not involve the creation of a corneal flap.

What are the differences between LASIK and LASEK?

  • LASIK involves creating a corneal flap, LASEK does not. 
  • LASEK involves removing the corneal epithelium, LASIK does not.
  • These 2 fundamental differences are key to the advantages and disadvantages of each procedure.
  • LASEK is associated with more discomfort than LASIK in the first 2 days after surgery.
  • The visual improvement is more rapid with LASIK; typically patients can see 2020 the day after surgery.
  • Return to contact sports or higher risk activities can be slightly delayed with LASIK until the corneal flap heals fully.
  • Thinner corneas or corneas with a slightly abnormal shape can be treated safely with LASEK.
  • Both procedures achieve the same visual outcome.

What are the differences between LASIK and SMILE?

  • SMILE is considered key-hole laser eye surgery as it only involves creating a 3mm opening in the cornea; typically LASIK has an opening of 18-20mm.
  • SMILE provides potentially better biomechanical stability of the cornea.
  • LASIK can treat a greater range of refractive errors; currently SMILE cannot be used to treat long-sightedness nor can it treat the need for reading glasses as does PRESBYOND LASIK.
  • SMILE can treat high short-sightedness potentially safer than LASIK.
  • LASIK requires the use of both femtosecond laser and excimer laser; SMILE only uses femtosecond laser.
  • Return to physical activities, especially contact sports and swimming, is more rapid with SMILE.
  • Due to the smaller incision (opening), SMILE preserves the corneal nerves better and thus has less potential to cause dry eye than LASIK.
  • Both procedures and their recovery are painless.


As you can see, there isn’t really a “best” procedure since it depends entirely on your circumstances. In some cases, LASIK is the best option. In others SMILE. And in different situations, LASEK/ASA could be the right choice for you. That’s why it’s important to consultant a specialise laser eye surgeon who can point you in the right direction. To find out if you’re suitable and discover which procedure is best for you, book a free screening today by clicking here.

About the Author:

Aris Konstantopolous
Aris Konstantopolous is a co-founder and medical director at Laser Vision Eye Centre. Along with David, he personally performs all of our procedures, consultations and assessments.

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