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Updated: Oct 23, 2025
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Quantification of Oculomotor Responses and Accommodation Through Instrumentation and Analysis Toolboxes
Published on: March 3, 2023
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Objective changes in astigmatism during accommodation
Francisco Lara-Lacárcel1, Iván Marín-Franch1,2, Vicente Fernández-Sánchez1
1Faculty of Optics and Optometry, University of Murcia, Murcia, Spain.
Summary
Astigmatism changes little with accommodation and convergence, except at high demands. Small shifts in the crystalline lens may cause minor changes in astigmatism power and axis.
Area of Science:
- Ophthalmology
- Optometry
- Vision Science
Background:
- Previous research indicates minor astigmatism changes during eye accommodation.
- Ocular cyclotorsion occurs at various gaze angles.
- Accommodation and convergence typically happen together.
Purpose of the Study:
- To investigate how astigmatism magnitude and axis change with accommodation at different convergence angles.
- To understand the interplay between accommodation, convergence, and astigmatic changes in the human eye.
Main Methods:
- Evaluated 15 subjects (20-49 years) with ≤1.5 D astigmatism.
- Used a Shack-Hartmann aberrometer for accommodation from +0.50 D to -10 D.
- Measured astigmatic changes at convergence demands of 0°, 5°, 10°, and 15°.
Main Results:
- No significant change in Jackson cross-cylinder J45 component during accommodation.
- J0 component shifted slightly with accommodation, varying with convergence demand.
- Average cylinder power changed by -0.05 D/Dacc to -0.08 D/Dacc, with axis shifting towards against-the-rule.
Conclusions:
- Clinically significant astigmatism changes were not observed for accommodation demands up to 4 D with convergence up to 15°.
- Minor astigmatic shifts may result from crystalline lens displacement during accommodation.
- Age did not significantly influence astigmatic changes in this study.
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