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Optics aberrations

Refractive surgery corrects optical aberrations by refining the corneal surface, thereby improving visual quality, especially in low-light conditions.

Until recently, the analysis of vision was expressed in terms of sphere (myopia or hyperopia), and cylinder (astigmatism) characterized by a power and an axis. In most cases the sphere and the cylinder combine to create sphero-cylindrical aberrations.

They are by definition called “LOW-DEGREE ABERRATIONS”.
These refractive errors are the basis of all corrections by corrective lenses which are always expressed (international name) in Sphere (cylinder and axis).

Example: -3.00 (-1.00 at 15°).

In recent years, research in optics and the availability of new devices (aberrometers) have made it possible to understand that vision is not only the association of low-degree errors, but the combination of multiple optical anomalies which integrate high-degree optical aberrations according to mathematical formulas called Zernike polynomials.

Defocus, symmetrical deformation, coma, trefoil

The best known are coma, spherical aberration, trefoil etc. these are the “HIGH DEGREE ABERRATIONS ”.
Thus, like a fingerprint, each individual presents a unique vision made up of the combination of multiple aberrations of low and high degrees.

In practice, the rate of high-degree aberrations does not exceed a very small percentage in most individuals, making it negligible to take these elements into account for laser treatment. Conversely, for some, the percentage of high-degree aberrations becomes sufficiently significant for personalized treatment to be necessary.

The Laser Mont-Blanc center is equipped with the entire system allowing personalized aberrometric processing: Analysis of all aberrations by the Wave Analyzer, the Topolyser Vario, the Pentacam and the use of specific processing software by the EX500 Alcon.