Abstract
(1) Background: The purpose of the study is to present a simple theoretical account of the effect of translation of coma and spherical aberrations (SA) on refractive error and higher order aberrations. (2) Methods: A computer software algorithm was implemented based on previously published methods. The effect of translation (0 to +1 mm) was analyzed for SA (0 to +2 µm) and coma (0 to +2 µm) for a circular pupil of 6 mm, without any rotation or scaling effect. The relationship amongst Zernike representations of various aberrations was analyzed under the influence of translation. (3) Results: The translation of +0.40 µm of SA (C[4,0]) by +0.25 mm with a pupil diameter of 6mm resulted in induction of tilt (C[1,1]), −0.03D defocus (C[2,0]), +0.03D astigmatism (C[2,2]) and +0.21 µm coma (C[3,1]). The translation of +0.4 µm of coma (C[3,1]) by +0.25 mm with a pupil diameter of 6 mm resulted in induction of tilt (C[1,1]), −0.13D defocus (C[2,0]) and +0.13D astigmatism (C[2,2]). A theoretical quantitative relationship between SA, coma, astigmatism and defocus is presented under the influence of translation. (4) Conclusion: The results can act as a guide for the clinician, in order to readily assess theoretical impact of wavefront map translation from pupil center to the visual axis. The resultant refractive coupling has to be taken into consideration especially when treating eyes with an abnormal corneal shape and/or large pupil center to corneal vertex chord.
Highlights
The human eye is an optical system comprising four main non coaxial optical elements
Due to the discrepancy between the optical center and the visual center, there exists a debate among clinicians in the refractive community about the choices made in the corrective strategy; whether the correction provided should maximize the quality of the wavefront at the fovea or whether it should focus on an overall improvement of the optical system
The overall effect of spherical aberrations (SA) and coma translation is summarized through the schematic presented in
Summary
The human eye is an optical system comprising four main non coaxial optical elements. The sharpest vision of a target is realized when it is in line with the fixation target and the fovea of the retina (called the visual axis). Due to the discrepancy between the optical center (projection of the optical axis on the retina) and the visual center (which corresponds to the fovea), there exists a debate among clinicians in the refractive community about the choices made in the corrective strategy; whether the correction provided should maximize the quality of the wavefront at the fovea or whether it should focus on an overall improvement of the optical system. The optical quality of human eyes is often described in terms of wavefront aberrations [1].
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
