Systems and methods for fine-tuning refractive shapes for vision treatment are provided. Techniques encompass determining a variable index of refraction for a cornea of the eye, and determining the refractive treatment shape for the eye based on the variable index of refraction. Techniques also encompass determining a variable radius of curvature of an anterior surface of a cornea of the eye, and determining the refractive treatment shape for the eye based on the variable radius of curvature.