Before we perform any laser procedure at Lions Laser Vision, we answer one question: does this eye have enough corneal tissue to safely reshape? For most patients the answer is yes, and SmartSight NOVA delivers excellent results with a quick recovery. But for patients with high prescriptions or thinner corneas, laser correction can reach its limit. That is where Implantable Contact Lenses (ICLs) come in. This is not about one procedure being better. It is about understanding why your surgeon might recommend a different path for your particular eyes.
What Laser Eye Surgery Actually Does to Your Cornea
Your cornea, the clear front surface of your eye, is responsible for about two-thirds of your eye’s focusing power. Laser eye surgery corrects vision by removing a thin layer of corneal tissue to change its shape, redirecting how light hits the retina.
With SmartSight NOVA, a femtosecond laser creates a tiny disc of tissue (called a lenticule) inside the cornea, and your surgeon extracts it through a small 3 mm incision. No flap is cut, no second laser is needed, and the outer layers of the cornea stay mostly intact. That is why SmartSight NOVA potentially preserves more corneal strength than LASIK, where a hinged flap must be created first.
The important takeaway: the stronger your prescription, the more tissue needs to come out. A mild script of -2.00D requires a very thin lenticule. At -8.00D, the lenticule is significantly thicker. And your cornea only has so much tissue to spare.
Your Cornea Has a Safety Threshold
The average human cornea is roughly 540 to 550 microns thick (about half a millimetre). That might sound like plenty, but a significant portion of that thickness is load-bearing structure that keeps your cornea stable against the natural pressure inside your eye. After any laser procedure, the untouched tissue underneath the treatment zone needs to remain at least 280 microns thick. Drop below that floor, and you increase the risk of a condition called ectasia, where the cornea gradually bulges and distorts because it is no longer strong enough to hold its shape.
Take a patient with an average cornea (540 microns) and a moderate prescription of -5.00D: comfortable room to work with. SmartSight NOVA delivers a full correction with a healthy safety margin. But take the same cornea with a script of -9.00D or -10.00D, and the tissue budget gets dangerously tight. For someone with a naturally thinner cornea (say, 490 microns), the limit arrives even sooner.
ICL: A Completely Different Approach
An Implantable Contact Lens works on the opposite principle. Instead of removing corneal tissue to change the eye’s focusing power, the surgeon adds a thin, biocompatible lens inside the eye. The cornea is left completely untouched. The lens (an EVO ICL) is made from Collamer, a material that combines a collagen-based polymer with soft contact lens material. Your body does not reject it, you cannot feel it, and nobody can see it. It sits behind the iris and in front of your natural lens, entirely hidden.
Modern EVO ICLs feature a tiny central opening (aquaport) that lets fluid flow naturally through the lens, eliminating the need for an additional laser hole in the iris that older designs required. This reduces risk of uncommon complications such as pupil block or cataract.
Critically, an ICL is also reversible. If your prescription changes significantly, or if better technology comes along, the lens can be removed and your eye returns to its original state. Corneal tissue, once removed by laser, cannot be put back.
How Your Surgeon Decides
The decision between SmartSight NOVA and ICL is not arbitrary. At your initial assessment, your surgeon maps your cornea in detail using advanced imaging, measuring its thickness, curvature, and structural health. From there, they calculate how much tissue a full laser correction would require and whether the remaining cornea would stay comfortably above the safety threshold.
If the numbers stack up, SmartSight NOVA is typically the recommendation. It is minimally invasive, recovery is fast (most patients return to work within a day or two), and the SCHWIND ATOS laser platform’s automatic centration and eye-tracking technology delivers exceptionally precise results.
If the numbers are tight, or if other risk factors are present, such as a naturally thinner cornea, family history of corneal conditions, or very high myopia, your surgeon will recommend ICL instead. For ICL candidates, the surgeon also measures the space inside the front of the eye to select the correct lens size, ensuring the implant sits at a safe distance from your natural lens for long-term stability. This is not a compromise. It is the procedure that respects the anatomy of your particular eye.
The Right Procedure for the Right Eye
SmartSight NOVA is our go-to for the majority of patients. It is safe, precise, and recovery is remarkably quick. But responsible refractive surgery means knowing when a different approach is the better call. For patients with high prescriptions or thinner corneas, an ICL is not a second choice; it is the technically correct one.
Whatever your prescription, the first step is always a thorough assessment. Our team at Lions Laser Vision will take detailed measurements of your eyes and walk you through the reasoning behind our recommendation, so you understand not just what we suggest, but exactly why.
Book your free suitability assessment at lionslaservision.com.au/suitability-test or call (08) 9381 0758.
Disclaimer: This article is intended for general educational purposes and does not constitute medical advice. Individual suitability for any procedure depends on a comprehensive clinical assessment. All surgical procedures carry risks. Please consult your ophthalmologist for personalised advice.
