When retopologizing an eye 3D model, stiffness usually comes from edge loops that don’t follow the eye’s natural curvature (like the iris or eyelid) or are too uniformly spaced.
Overly rigid edge flow restricts deformation—if loops don’t radiate from the iris or follow eyelid folds, animations like blinking or eye movements will look unnatural and stiff.
To fix this, redraw edge loops to mirror the eye’s anatomy (e.g., curved lines around the iris) or add extra edges in flexible areas (like the eyelid crease) to improve how the model bends.