Human eye model with optic nerve segment and surrounding tissues

Herein, we constructed a finite element human eyeball model, encompassing a biophysically detailed retinal layer, optic nerve segment, and its surrounding tissues, as well as extraocular electrodes.A multi-conductivity 3D human eye model was constructed based on the AC/DC module in COMSOL Multiphysics. This model encompassed essential eye structures, such as the cornea, atria, lens, vitreous body (VB), retinal, choroid, sclera. Additionally, it incorporated more biological components on the nasal side of the model, such as the optic nerve, cerebrospinal fluid (CSF), and the optic nerve sheath.Specifically, the optic nerve segment was positioned at a 22.5° angle relative to the model’s central axis, slanting horizontally to the nasal side. The portion intersected with the eyeball wall resembled a truncated cone, while the protruded section formed a cylinder. Eventually, the optic nerve, CSF, and optic nerve sheath were aligned as coaxial cylinders. Based on reported data, the anterior segment of intraconal fat and muscle was shaped like a hemisphere, while the segment resembled a cone deviated to the optic nerve. For TI stimulation, a single extraocular electrode was chosen in the form of a Platinum (Pt) disc, measuring 500μm in diameter and 50μm in thickness.