What happens if I move my eyes during Laser Eye Surgery?

leading laser eye surgeon at the London Vision Clinic

Clutching a sharp bladed instrument the surgeon calmly says to the patient, “Don’t worry, I’ve done this hundreds of times before and haven’t made a mistake yet.”

Not entirely filled with confidence, the patient smiles, and the surgeon accepts the gesture to begin manually slicing a precise flap in their cornea. Then, using a scalpel, he pries the wafer-thin flap away and winks at the patient, who by this time has huge globules of sweat running down their face and is thinking over and over “please God don’t move”.

This was the typical experience of a patient undergoing Laser Eye Surgery in the 20th century, when laser technology was  in its infancy and bladeless procedures were yet to be widely introduced.

‘Bladeless’ Laser Eye Surgery emerged on the scene in 1999 with the very welcome development of the femtosecond laser — a high-energy laser that took Laser Eye Surgery from a part-manual procedure to one that’s pretty much fully-automated.

This technology was first utilised by a US company in a procedure known as IntraLase, going on to later evolve into the incredibly precise femtosecond laser seen in many clinics today.

Rather than unreliable human hands and eyesight acting as the tools for conducting the precision surgery, modern Laser Eye Surgery clinics use the Excimer laser — produced by the renowned optics company Carl Zeiss Meditec — to ensure auto-stabilised delivery and unparalleled accuracy.

In fact, results from rigorous FDA trials of Carl Zeiss Meditec’s latest model, the Zeiss MEL 90 Excimer laser, shows it to be the most accurate LASIK laser in the world. This removes human error from the procedure — the main source of complications in Laser Eye Surgery.

Cutting-edge tracking technology means no need to worry about moving your eyes during Laser Eye Surgery

Prof. Dan Reinstein explains how eye-tracking uses cameras to ensure moving the eye does not affect the outcome of Laser Eye Surgery.

Along with the latest in laser technology, we now have access to a myriad of other safety systems that greatly improve and control the laser eye procedure.

One such development that ensures if you move your eyes during Laser Eye Surgery — or even fall from the bed — the results aren’t affected, is eye-tracking technology.

Eye tracking works by photographing the eye as many as 500-1000 times a second. Each photograph is analysed to determine the position of the eye is in exactly the right place for the laser treatment — if it’s not, it instantaneously compensates for the movement.

“[eye-tracking] means that during treatment, and many people worry what if I move my eye or what if I blink, am I going to go blind… you could probably be playing tennis and still get the treatment at the same time put in the right place, because eye trackers today are able to place the spots to within a 10th of a millimeter of where you want to place it.”

An important factor in the precision of Laser Eye Surgery treatment is the spot size of the laser. As the point where the laser touches the eye, the spot is better to be finer than broader; it’s a bit like how a pencil tip is used for incredibly detailed work, whereas a paintbrush can only create manage much larger strokes. The finer the spot, the more focused it is, which means the laser only removes the tissue it needs to. Many lasers have different spot sizes, so the exact spot size of your laser will depend on which Laser Eye Surgery clinic you choose.

The Zeiss MEL 90 Excimer laser has the smallest spot size available. With the ability to move around the eye at a fast rate and react very quickly, this makes for precise and complication free Laser Eye Surgery.

Think you’ll move, sneeze, or catapult out of the bed during Laser Eye Surgery? Let us know in the comments below!