A shell model of eye growth and elasticity

TL;DR

This paper introduces a simplified shell model of eye growth that captures the coupling between elasticity, growth, and visual stimuli, providing insights into emmetropization mechanisms.

Contribution

It presents a novel axisymmetric hyperelastic shell model of the eye that enables analytical evaluation of growth feedback and shape regulation during development.

Findings

Local growth laws can effectively tune eye size and shape.

The model demonstrates robustness across various parameters.

It offers a tractable framework for studying eye development.

Abstract

The eye grows during childhood to position the retina at the correct distance behind the lens to enable focused vision, a process called emmetropization. Animal studies have demonstrated that this growth process is dependent upon visual stimuli, while genetic and environmental factors that affect the likelihood of developing myopia have also been identified. The coupling between growth, remodeling and elastic response in the eye is particularly challenging to understand. To analyse this coupling, we develop a simple model of an eye growing under intraocular pressure in response to visual stimuli. Distinct to existing three-dimensional finite-element models of the eye, we treat the sclera as a thin axisymmetric hyperelastic shell which undergoes local growth in response to external stimulus. This simplified analytic model provides a tractable framework in which to evaluate various emmetropization hypotheses and understand different types of growth feedback, which we exemplify by demonstrating that local growth laws are sufficient to tune the global size and shape of the eye for focused vision across a range of parameter values.