In this study, we present a finite-element-based investigation of the biomechanical responses of the human eye under combined G-force loading and physiological intraocular pressure (IOP), with an emphasis on implications for ophthalmic sensing and measurement reliability. Three-dimensional eye models with different axial lengths were constructed and imported into ANSYS to perform modal and transient dynamic analyses. Modal analysis revealed that an increase in axial length consistently reduced the natural frequencies across all vibration modes, while the corresponding mode shapes remained largely unchanged, indicating preserved structural deformation patterns despite geometric variation. Dynamic simulations were conducted by constraining the eyeball to displace only along the primary loading axis, with external acceleration gradually increased from 1 to 6G. Within a normal human IOP of 20 mmHg, the resulting stress, strain, and pressure distributions in the optic nerve were systematically analyzed for eyes with different axial lengths. The results demonstrate that axial length significantly affects the magnitude and spatial distribution of optic nerve mechanical responses under different G-force levels, suggesting a nonnegligible coupling effect between ocular geometry and external dynamic loading. From a sensing perspective, these findings provide quantitative mechanical indicators that are critical for the calibration, interpretation, and validation of ophthalmic pressure and strain-related sensors. The primary objective is to clarify how ocular axial length affects optic nerve mechanical responses under different G-force levels at a normal IOP. However, the analysis is limited to numerical simulations with simplified material properties and boundary conditions, without direct experimental validation. Future investigations will be focused on improving the biomechanical representation of ocular tissues and evaluating the predicted responses under controlled experimental loading conditions. The proposed numerical framework offers a reliable platform for evaluating ocular biomechanical behavior under dynamic environments, thereby supporting the development of sensor-assisted diagnostic tools and enhancing the accuracy of eye-related biomechanical measurements in both clinical and aerospace contexts.