The concept of cone opponency may extend beyond accommodation, to myopiagenesis and emmetropization, for a better peripheral defocus lens

Abstract

Myopia has ever-rising prevalence in the past few decades globally. Its pathogenesis is still not adequately elucidated especially at the signal transduction level. For the environmental risk factors, there is a large body of fragmented knowledge about the visual inputs for accommodation, myopiagenesis and emmetropization, with the latter two being essentially local processes. The red-green and yellow-blue chromatic pathways, together with the underlying L-M and S-(L+M) cone opponency, seem to be the common denominator amongst them. In this review, experimental and observational evidence are summarized to delineate the interplay of them. This review may establish the pivotal role of longitudinal chromatic aberration (LCA) for a mechanistic approach to future research in myopia control. This review looks into the mechanistic processes underlying myopiagenesis and emmetropization, specifically focusing on chromatic aberration and cone opponency in vision as pivotal components. The roles of longitudinal chromatic aberration (LCA) and cone contrast in myopia onset and development are intriguing. How visual input and chromatic pathways (specifically, red-green and blue-yellow cone opponency) contribute to accommodation that may trigger emmetropization mechanisms, thereby influencing eye growth patterns are explored and discussed. In brief, this manuscript delves into the physiology of visual processing and highlights a foundational aspect of visual science that may account for a "Go" or "Stop" signaling in axial eye growth. It further proposes a metric to gauge myopia-inhibiting optical devices such as the peripheral defocus lenses, for its best iteration. Future research in the above-mentioned areas is warranted.

Keywords: Accommodation; Cone-contrast; Defocus; Emmetropization; Myopia.