A method for estimating and tracking refractive error progression of an individual includes estimating a percentile of Spherical Equivalent Refraction (SPHEQ) as a function of at least the individual's age by comparison to a reference population; estimating an expected SPHEQ trajectory over a future predetermined period of time; comparing the expected SPHEQ trajectory with the reference population; and comparing the expected SPHEQ trajectory with an expected SPHEQ trajectory using an ametropia control treatment, thereby showing a possible treatment benefit over the predetermined period of time.