What's the difference between the kinds of laser eye surgery?

It can be a bit confusing to understand the different laser procedures available. Currently there are 3 main types: LASIK, SMILE and surface laser (PRK/ASLA). All 3 work on the same engineering principle- to correct a certain glasses prescription a certain amount of tissue needs to be removed from the cornea in a certain defined shape. The cornea is the front lens of the eye. The difference lies in how that shape is accessed and removed.

With LASIK, a flap is created with a femtosecond laser and then lifted to expose the area underneath. An excimer laser then ablates or vaporises the tissue in the shape required. The flap is then put back. The advantage of the flap is rapid recovery but dry eye is more common.

With SMILE, a femtosecond laser creates the shape in 3D space within the cornea a bit like 3D printing. Then through a keyhole access point, this 3D shape is physically removed. The keyhole entry point means less dry eye generally than LASIK but slightly slower recovery. SMILE also tends to be more accurate for higher degrees of short sightedness because there is no exposure to the elements during the shaping process.

With surface laser (PRK/ASLA), the top skin layer is removed with an excimer laser or a weak alcohol solution and then the excimer laser ablates the tissue in the required shape. So it's like LASIK without the flap.

Make sense? Ultimately your eye surgeon will recommend what they think is the best procedure for you but knowledge is always a good thing :)

* Information on this blog is general in nature and should not be taken as professional medical advice or as a substitute for a consultation with a medical professional.