Differences Between SMILE LASIK, CLEAR LASIK, and SMART LASIK (2025)
Written by Gangnam Brand Eye Clinic
2025.02.20
There are various methods for vision correction surgery. The earliest procedures, LASIK and LASEK, were developed based on the idea of reshaping the cornea to correct refractive errors. These surgeries have remained widely used due to their proven safety, effectiveness, and good visual outcomes with minimal complications. Over time, a new procedure called SMILE LASIK was developed, combining the advantages of both LASIK and LASEK. It has become particularly beneficial for individuals who need a quick recovery and a fast return to daily activities after surgery. While LASIK, LASEK, and SMILE LASIK are well-known, there is limited information available on newer procedures like CLEAR LASIK and SMART LASIK. Therefore, this article aims to introduce these advanced techniques and explain how they differ from conventional vision correction surgeries.
SMILE LASIK: The Next-Generation Vision Correction with Faster Recovery and Enhanced Safety
LASIK is a vision correction surgery that minimizes exposure to the surgical area, resulting in less pain and a faster visual recovery. However, compared to LASEK, LASIK carries a higher risk of flap-related complications due to the possibility of flap displacement from external impact or trauma. On the other hand, LASEK does not create a corneal flap, meaning there is no risk of flap-related complications, making it more resistant to external impacts. However, LASEK tends to cause more post-operative discomfort and takes longer to heal compared to LASIK. Because LASIK and LASEK have clear advantages and disadvantages, there has been a growing demand for a new surgical method that combines fast recovery with enhanced safety. In response, Carl Zeiss Meditec developed SMILE LASIK (3rd-generation vision correction surgery) using the VisuMax laser system. The full name of SMILE LASIK is SMILE (SMall Incision Lenticule Extraction), referring to its technique of removing a lenticule (a thin layer of corneal tissue) through a small incision. The surgical process involves: - Using a femtosecond laser to create a 2mm micro-incision, significantly smaller than the 20mm flap incision in LASIK. - Reshaping the corneal stroma by cutting and extracting the lenticule through the micro-incision. Since the external incision is only 2mm, SMILE LASIK causes significantly less post-surgical pain and allows for faster recovery compared to traditional LASIK. Additionally, because the incision remains partially connected to the inner corneal layers, the surgery provides greater long-term corneal stability. Compared to previous refractive surgeries, SMILE LASIK also offers: - Lower risk of dry eye syndrome due to minimal nerve disruption. - Reduced likelihood of corneal haze or myopia regression. - Increased overall safety and stability, marking a significant advancement in vision correction technology.
SMILE LASIK, and Next?
However, SMILE LASIK was developed in 2002, and despite its advancements, it still has limitations. The procedure involves manual steps that depend heavily on the surgeon’s skill, which can lead to surgical variability. Additionally, patients whose eyes naturally rotate (torsional eye movement) in different positions may experience reduced accuracy due to the technique’s limitations. As vision correction technology continued to evolve, researchers identified and improved upon SMILE LASIK’s shortcomings. This led to the development of CLEAR LASIK (4th-generation) using Ziemer’s Femto Z8 and SMART LASIK (5th-generation) using Schwind’s ATOS. Fundamentally, SMILE LASIK, CLEAR LASIK, and SMART LASIK share the same surgical technique. The reason CLEAR LASIK and SMART LASIK are not branded as "SMILE LASIK" is that the term "SMILE" is trademarked, preventing other companies from using it. However, all three procedures follow the SMILE technique, meaning they remove the corneal lenticule through a small incision.
CLEAR LASIK (4th Generation) – Using Ziemer’s Femto Z8
CLEAR LASIK utilizes the Femto Z8 laser by Ziemer, which offers improvements over traditional SMILE LASIK: Uses lower energy and faster laser pulses, creating a smoother lenticule incision. Traditional SMILE LASIK requires precise manual eye fixation, making it more dependent on the surgeon’s skill. In contrast, CLEAR LASIK allows laser-center positioning adjustments even after fixation, reducing surgical variability and improving precision. These improvements help make CLEAR LASIK a more consistent and stable procedure while maintaining the advantages of the SMILE technique.
SMART LASIK (5th Generation) – Using Schwind’s ATOS
SMART LASIK is a 5th-generation vision correction surgery developed using the ATOS laser system by Schwind. Schwind is well known for its Amaris Red excimer laser, which has established a dominant position in LASIK and LASEK procedures. By integrating its advanced laser technology into SMART LASIK, Schwind has combined the low-energy, high-speed precision of 4th-generation lasers with enhanced tracking and correction systems for improved surgical outcomes. Key Advantages of SMART LASIK (5th Generation) - Uses low-energy laser pulses for a smoother and more precise lenticule extraction, similar to CLEAR LASIK (4th generation). - Features 7D eye-tracking technology, which detects even slight involuntary eye movements during surgery to maintain laser accuracy. - Introduces automatic torsion compensation technology, which corrects eye rotation that occurs when lying down for surgery. How Does This Improve Upon SMILE LASIK (3rd Generation)? - SMILE LASIK does not have automatic eye rotation correction. If a patient’s eyes rotate when lying down, surgeons must manually mark the cornea with a pen and adjust accordingly. - SMART LASIK automates this process, ensuring more precise astigmatism correction and overall accuracy. With these advancements, SMART LASIK provides an even more stable and accurate vision correction procedure, reducing surgeon dependency and improving long-term outcomes.
In Summary
In summary, from SMILE LASIK to the latest SMART LASIK, all these procedures share the same fundamental surgical method, meaning they all offer fast visual recovery, a quick return to daily activities, and a high level of safety. However, as each new generation has evolved, advanced laser systems have introduced automated error correction, reducing the impact of surgical variables. This has allowed for greater customization based on each patient's unique eye characteristics, leading to: - Higher surgical accuracy - Fewer complications - Greater overall patient satisfaction with vision quality With these continuous advancements, modern vision correction surgeries are becoming more precise, stable, and adaptable to a wider range of patients.
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