What is Lasik?

The History
The idea of wavefront analysis existed long before surgical refractive procedures were practiced and/or excimer lasers invented. Wavefront analysis has its roots in astronomy.

In the 1900s, an astrophysicist named Johannes Hartmann devised a method of measuring the ray aberrations of mirrors and lenses. He wanted to isolate rays of light so that they could be traced and any imperfections in the mirror could be seen.

The Hartmann test consisted of using a metal disk in which regularly spaced holes had been drilled. The disk or screen was then placed over the mirror that was to be tested and a photographic plate was placed near the focus of the mirror. When exposed to light, a perfect mirror will produce an image of regularly spaced dots. If the mirror does not produce regularly spaced dots, the irregularities, or aberrations, of the mirror can be determined.

Source: Image from the Center for Visual Sciences, University of Rochester

Around 1971, Dr. Roland Shack and Dr. Ben Platt advanced the concept by replacing the screen with a sensor based on an array of tiny lenslets. Today, this sensor is known as the Hartmann-Shack sensor. Hartmann-Shack sensors are used in a variety of industries: from the military, to astronomy, and now in ophthalmology.

Source: Image from ASIC Laboratory Heidelberg

Dr. Josef Bille, of Germany, was the first person to use the Hartmann-Shack sensor in ophthalmology. Other wavefront pioneers include Dr. Junzhong Liang and Dr. David Williams. These doctors built upon the each other_s achievements until a wavefront device that could be used in a clinical setting, was developed. Prior to that, the technology was extremely complex. However, the current wavefront device, developed by Dr. Williams and Dr. Liang, has been automated resulting in increased speed and accurac

In 1997, Dr. Liang and Dr. Williams presented a paper at ARVO (The Association for Research in Vision and Ophthalmology) that discussed the early clinical results attained with the wavefront device. At this time, ophthalmologists began to take a serious look at the possibilities of wavefront technology for correcting refractive error. The major laser manufactures; VISX, Bausch & Lomb, and Alcon then approached Drs. Bille, Williams, and Liang to develop their own wavefront analyzers.