Fig. 1

The unadjusted changes in spherical equivalent refraction (SER) and axial length (AL) over the 5-year study for HAL and ESVL groups. a SER changes; b AL changes. Error bars represent standard errors of the mean. HAL, spectacle lenses with highly aspherical lenslets; SVL, single-vision spectacle lenses (data from the 2-year clinical trial); SVL2, single-vision spectacle lenses (data from a 1-year extended study of the same clinical trial); ESVL, extrapolated single-vision spectacle lenses (data was calculated based on the 2-year data from the SVL group in the same clinical trial, and the data for the following 3 years was estimated by assuming an annual reduction in SER by 9.7% [22] and in AL by 15% [23]