Optical and Visual Diet in Myopia.

The alarming increase in myopia prevalence in modern times is attributed to environmental changes affecting young individuals. Visual scenes are projected onto the retina by the eye's optical components and sampled by retinal photoreceptors, shaping the spatial, temporal, and chromatic "visual diet" fed to the visual system. These inputs provide essential signaling for proper emmetropization and, in eyes that develop myopia, trigger the cascade of events leading to excessive axial elongation. This article offers foundational components for formulating computational models of myopic eyes and highlights available and needed optical and structural data to construct longitudinal three-dimensional optical eye models in emmetropes and developing myopes. These wide-angle eye models, in both relaxed and accommodated states, will enable understanding of the changes the eye undergoes at myopia onset and potentially allow exploration of cause-effect relationships in myopia development. Age- and refractive-dependent eye models also serve as platforms to test the coupling of novel optical treatments for myopia control with the resulting blur patterns across the retina. Chromatic, spatial, and temporal stimuli are explored as plausible cues for emmetropization. The article also reviews published theories on mechanisms for encoding the sign of defocus and triggering axial elongation. Fully quantitative technologies for ocular geometrical, biometric, and optical evaluation, as well as for monitoring physical features of the environment, are critical for collecting multidimensional data sets that enable predictive models. Given that time spent outdoors is a major factor associated with myopia development, exploring mechanisms that connect light exposure with myopia is paramount. The article also reviews current proposed mechanisms linked to retinal dopaminergic pathways, dysfunction of melanopsin signaling, and disruption of circadian rhythms-factors altered in modern lifestyles by artificial illumination and prolonged use of digital displays. Understanding the interplay between distinct environmental attributes (e.g., light intensity, spatial frequency distribution, blur, spectral characteristics) and the filtering effects of ocular optics will help elucidate pivotal myopiagenic signals and potentially unveil the complex, multifactorial mechanisms relevant for myopia management. Additionally, an annex appended to the article discusses unresolved inquiries and promising research directions in myopia research, drawing from expert insights.