Abstract: The onset and progression of myopia are closely related to the visual signals received by the retina, including optical defocus and contrast signals. This review systematically integrates evidence from optical modeling, animal studies, and clinical trials on myopia control lenses based on Simultaneous Competing Defocus (SCD) and Diffusion Optics Technology (DOT), and proposes a cascaded regulatory framework of “retinal ON/OFF pathway rebalancing → choroidal response → slowed scleral remodeling.” At the optical level, SCD lenses weaken mid-high spatial frequency input via myopic defocus in the spatial domain, whereas DOT lenses implement a mild, wide-field reduction of contrast in the signal-intensity domain while striving to preserve central clarity. At the physiological level, both types of lenses are characterized by reduced OFF-pathway activity, relatively enhanced ON-pathway activity, concomitant choroidal thickening, and a decreased rate of scleral remodeling. At the clinical level, prospective and randomized controlled studies suggest that their inhibitory effects on refractive progression and axial elongation are of a similar magnitude, and that the effect size is associated with treatment adherence and daily wearing time.

Key words: Myopia prevention and control, Contrast sensitivity