Advancement of Optical Technology and Vision Correction Surgery

 

Recently, as author Han Kang received the Nobel Prize in Literature, it drew significant attention not only internationally but also domestically.

What many may not know is that SMILE, the vision correction surgery we’ve been consistently introducing, is also deeply connected to the Nobel Prize. Today, we’d like to talk about how modern optical technology, particularly the femtosecond laser, has influenced vision correction surgery.

1. Femtosecond Laser – A Product of Optical Technology

In 2018, the Nobel Prize in Physics was awarded to three scientists who pioneered innovative techniques in the field of laser physics. When handling extremely small and precise objects, conventional tools like tweezers or forceps are limited, especially when manipulating minuscule substances such as atoms or molecules.

These tiny materials are difficult to observe with the naked eye and even harder to manipulate directly.

However, the phenomenon that laser light can exert pressure to pull particles toward the center was discovered, leading to the development of optical tweezers.

Thanks to this technology, scientists can now manipulate microscopic biological materials—such as viruses, bacteria, and even living cells—using lasers. The 2018 Nobel laureates Arthur Ashkin, Gérard Mourou, and Donna Strickland made groundbreaking advances in technologies that enable the precise handling of extremely small substances using light.

Their research has been highly praised for laying the groundwork for the development of precision tools in both industrial and medical fields.

▲ From research materials on the basic principles of chirped pulse amplification, in which Professor Strickland participated

The achievements of these three researchers led to the development of an advanced technology known as the femtosecond laser.

Thanks to its innovative characteristics, femtosecond laser technology has opened up new possibilities in the medical field—especially in vision correction surgery. This laser can pass through the epithelial layer of the cornea and act precisely only on the stromal layer, making it highly regarded as an optimized technology for vision correction.

SMILE (Small Incision Lenticule Extraction) is a procedure based on this femtosecond laser technology. It improves vision by removing a small portion of the corneal stroma through a minimally invasive incision.

▲ Research materials on the development of ultra-high-power lasers and the evolution of output enhancement

The most important characteristic of the femtosecond laser is that its ultra-fast light pulses are designed to affect only the target tissue with precision.

Compared to the femtosecond laser, the excimer laser—commonly used in LASIK and LASEK—has higher energy and a longer wavelength.

Lasers with long wavelengths have a limitation in that they can affect surrounding tissues before reaching the target area.

As a result, surgeries using excimer lasers are performed using methods such as LASIK, which involves creating a corneal flap before reshaping the inner tissue, or LASEK, which removes the corneal epithelium before correcting the stroma underneath.

▲ Femtosecond laser that removes only the stroma while passing through the corneal epithelium without damage

On the other hand, the femtosecond laser operates with an extremely short wavelength and high speed, giving it a technological advantage by precisely cutting only the target area without damaging surrounding tissues.

Thanks to this technology, a new method was introduced that allows direct correction of the corneal stroma without creating a flap or removing the epithelium.

As a result, corneal damage is minimized, patients experience little to no pain, and thermal scars or side effects are significantly reduced.
This advancement has become a core technology that made the innovative procedure known as SMILE possible.

SMILE has overcome the limitations of traditional LASIK and LASEK, significantly lowering the incidence of side effects such as dry eye syndrome, corneal haze, and keratoconus.
It is now recognized as a representative innovation born from the fusion of modern optical technology and medicine.

2. Zeiss and the Femtosecond Laser

A leading medical device that incorporates the aforementioned femtosecond laser technology is the VisuMax by Zeiss.
VisuMax uses precise femtosecond-level lasers to extract the corneal stromal lenticule, which is essential in the SMILE procedure.

▲ Optical components used in ZEISS's extreme ultraviolet (EUV) lithography equipment / Source: ZEISS SMT website

Zeiss is a global company that has greatly contributed to the advancement of science, medicine, and industry through innovations in optical technology.
In the 19th century, Zeiss’s optical microscope laid the foundation for the discovery of the tuberculosis bacterium in 1882, and the following year played a crucial role in identifying the cholera pathogen.

In the 20th century, Zeiss cameras were used during the Apollo 11 moon landing in 1969. Throughout the 1970s and 1980s, Zeiss popularized high-quality cameras and led the era of widespread consumer electronics.
Zeiss’s optical technologies are widely used across various industries, including microscopes, industrial measurement devices, eyeglass lenses, and semiconductor manufacturing equipment for smartphones.

Based on Zeiss’s long history of research and accumulated technologies, the VisuMax was developed. It enables innovative surgeries by precisely controlling the depth and location to extract the lenticule without damaging the front part of the cornea, correcting myopia and astigmatism.
Through the SMILE technology, Zeiss has significantly contributed to over 10 million SMILE surgeries performed worldwide.

Among these, more than 1.5 million surgeries have been successfully carried out in South Korea, clearly demonstrating the important position VisuMax holds in the field of vision correction surgery.

Moving beyond the era when LASEK and LASIK were the main methods of vision correction, SMILE now improves many people’s eyesight in a safer and more efficient way.
SMILE is a state-of-the-art vision correction procedure combining modern precision optical and medical technologies, and its safety and effectiveness have already been proven worldwide.

In South Korea as well, abundant clinical data and experience accumulated through various cases have established SMILE as a trusted method.
We hope today’s introduction was informative and helpful.

We will continue to strive to provide you with a variety of information related to lasers in the future.

Thank you for your time!