The potential role of fixation eye movements in the development of myopia

Myopia, a globally public health problem, referring to an abnormal refractive state in which the focus falls in front of retina due to extended axial length, is always regarded as an excessive emmetropia process and extreme ocular growth. Fixation eye movements (FEMs), small eye movements occurring incessantly during our gazes to maintain continuous attention and keep clear vision, have been considered to participate in the emmetropization process, yet their role in relation to myopia development has not been clearly demonstrated. It is possible that abnormal fixation eye movements could contribute to the onset and progression of myopia. Although the role of fixation eye movements (FEMs) in the setting of myopia has not yet been investigated, previous researches have demonstrated that patients with myopic refractive error performed significantly abnormal FEMs characteristics, suggesting the potential association between FEMs and myopia development. In this article, we hypothesized that abnormal fixation movements would result in disturbed spatiotemporal and defocus visual signal, abnormal longitudinal chromatic aberration, amplified eye-growth signal and extraocular muscle pressure, thereby inducing myopia development. In order to dissect any association between FEMs and myopia, further work is required to prospectively investigate the characteristics of FEMs during development and/or in populations affected by myopia or hyperopia. Future studies will be needed to update new understanding of myopia mechanism and propose suggestive prevention measures.