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Related Experiment Video

Updated: Jul 14, 2026

Correction of Presbyopia by Monocular Bi-Aspheric Ablation Profile

Published on: September 20, 2024

Corneal asphericity and spherical aberration.

Antonio Calossi¹

¹calossi@tin.it

Journal of Refractive Surgery (Thorofare, N.J. : 1995)

|May 26, 2007

Summary

Corneal asphericity, curvature, and pupil size significantly impact anterior corneal longitudinal spherical aberration. Understanding these relationships is crucial for refractive surgery outcomes.

Area of Science:

Ophthalmology
Optics
Biomedical Engineering

Background:

Corneal asphericity is a key parameter influencing ocular optics.
Longitudinal spherical aberration (LSA) affects visual quality and depth of focus.
Standardizing asphericity notations is essential for clear communication in research and clinical practice.

Purpose of the Study:

To consolidate various asphericity notations and their conversion factors.
To elucidate the influence of corneal asphericity, curvature, and pupil diameter on anterior corneal LSA.

Main Methods:

Finite ray tracing was employed using a conic section model for the anterior cornea.
Simulations involved varying corneal curvatures, asphericities, and entrance pupil diameters.

More Related Videos

$Comparison of Agreement and Accuracy using Binocular Wavefront Optometer with Autorefractor and Phoropter$

Comparison of Agreement and Accuracy using Binocular Wavefront Optometer with Autorefractor and Phoropter

Published on: September 16, 2025

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Last Updated: Jul 14, 2026

Correction of Presbyopia by Monocular Bi-Aspheric Ablation Profile

Published on: September 20, 2024

$Comparison of Agreement and Accuracy using Binocular Wavefront Optometer with Autorefractor and Phoropter$

Comparison of Agreement and Accuracy using Binocular Wavefront Optometer with Autorefractor and Phoropter

Published on: September 16, 2025

Main Results:

LSA increases quadratically with entrance pupil diameter when asphericity is constant.
LSA is a function of asphericity, refractive index, and radius of curvature for a fixed pupil.
Corneal steepening increases LSA, while flattening decreases it, with implications for refractive surgery.

Conclusions:

A conversion chart for asphericity notations and their corresponding LSA values is proposed.
A diagram to guide asphericity selection for maintaining physiological LSA post-refractive surgery is suggested.
These tools could enhance outcomes in corneal refractive surgery.