The best way to retopologize an eye 3D model balances manual precision for anatomical details with automatic tools for efficiency, focusing on quad-dominant topology that follows the eye’s natural curvature.
Align edge loops with critical features—like the iris/cornea boundary, eyelid creases, and sclera’s smooth surface—to ensure natural deformations (e.g., blinking). Use manual tools (Blender’s RetopoFlow, Maya’s Quad Draw) for detailed areas and auto-retopo (ZBrush’s ZRemesher) for simpler parts like the sclera base.
Test the mesh with shape keys (e.g., squinting) to check for stretching; if edges pull unevenly, refine loops around the lids or iris.