A morphoelastic shell model of the eye

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, but dependent on genetic and environmental factors that affect the
likelihood of developing myopia. The coupling between optical signal, growth, remodeling, and elastic response
in the eye is particularly challenging to understand. To analyse this coupling, we develop a minimal morphoelastic 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 morphoelastic model
provides a tractable framework in which we can evaluate various emmetropization hypotheses and understand
different types of growth feedback. As an example, we demonstrate that local growth laws are sufficient to
tune the global size and shape of the eye for focused vision across a wide range of parameter values.