HIF1A and myopia: Hypoxia in sclera microenvironment activates hypoxia inducible factor-1a (HIF-1a) signal pathway, promotes fibroblast differentiation into myofibroblasts, and reduces type 1 collagen synthesis, cause scleral extracellular matrix remodeling, scleral thinning, and eventually lead to axial elongation and myopia.