Related Experiment Video
Updated: Jun 22, 2026
08:27
Quantification of Oculomotor Responses and Accommodation Through Instrumentation and Analysis Toolboxes
Published on: March 3, 2023
Autonomic correlates of ocular accommodation and cardiovascular function
Leon N Davies1, James S Wolffsohn, Bernard Gilmartin
1Ophthalmic Research Group, School of Life and Health Sciences, Aston University, Birmingham, B4 7ET, UK. l.n.davies@aston.ac.uk
Summary
Near visual tasks impact heart rate by reducing parasympathetic nervous system activity, showing a link between eye and cardiovascular systems. Accommodative effort alone does not create autonomic differences across refractive groups.
Area of Science:
- Ophthalmology and Neuroscience
- Cardiovascular Physiology
- Autonomic Nervous System Function
Background:
- Ocular accommodation, the eye's ability to focus on near objects, involves complex neural control.
- Cardiovascular function is regulated by the autonomic nervous system (ANS), with sympathetic and parasympathetic branches.
- Understanding the interplay between visual demands and cardiovascular responses is crucial for holistic health insights.
Purpose of the Study:
- To investigate the relationship between objective measures of ocular accommodation (open- and closed-loop) and systemic cardiovascular function.
- To determine if autonomic nervous system activity mediates the link between accommodation and cardiovascular responses.
Main Methods:
- Sixty young adults (18-33 years) with varying refractive errors participated.
- Objective accommodative responses were measured using an autorefractor during various visual demands.
- Simultaneous heart rate was recorded, and its cardiovascular function analyzed in the frequency- and time-domains using Fast Fourier Transformation.
Main Results:
- Increased closed-loop accommodative demand correlated with a rise in heart rate (approx. 2 beats/min per 4.0 D).
- This heart rate increase was primarily due to reduced parasympathetic nervous system input (absolute and normalized).
- Refractive error did not significantly influence the accommodative-cardiovascular relationship.
Conclusions:
- Sustained accommodation effort shows a covariation between oculomotor and cardiovascular systems, indicating near visual tasks influence cardiovascular behavior.
- Accommodative effort alone is insufficient to cause autonomic differences between refractive groups.
- Both oculomotor and cardiovascular systems appear primarily influenced by changes in the systemic parasympathetic nervous system.
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