Prevalence of myopia and vision impairment due to myopic macular degeneration and myopia-related optic neuropathies have markedly increased worldwide. We evaluated whether myopia is associated with the prevalence of other ocular disorders in a positive or negative sense.Population-based studies conducted in Russia, China and India.The Russian Ural Eye and Medical Study (UEMS) and the Beijing Eye Study (BES) included 5899 individuals and 4439 individuals (all aged 40+ years), respectively, and the Central India Eye and Medical Study (CIEMS) consisted of 4711 individuals, aged 30+ years. The studies were conducted in rural and urban regions in Bashkortostan/Russia, Nagpur/India, and Beijing/China.The participants underwent a series of ophthalmological and general medical examinations.Axial length as surrogate for myopia, and prevalence of diabetic retinopathy (DR), age-related macular degeneration (AMD), angle-closure glaucoma (ACG), and open-angle glaucoma (OAG).In the UEMS, DR prevalence (OR:0.73;95%CI:0.56,0.96), AMD prevalence (OR:0.85;95%CI:0.74,0.98) and ACG prevalence (OR:0.72;95%CI:0.55,0.95) decreased, and OAG prevalence (OR:1.65;95%CI:1.45,1.88) increased with longer axial length in multivariable analyses. In the CIEMS, lower AMD prevalence (OR:0.81;95%CI:0.69,0.95) and lower ACG prevalence (OR:0.55;95%CI:0.36,0.83), and higher OAG prevalence (OR:1.45;95%CI:1.15,1.83) were associated with longer axial length. DR prevalence (0.33%;95%CI:0.16,0.50) was too low for statistical analysis in the CIEMS. In the BES, prevalence (OR:0.64;95%CI:0.50,0.81) and 10-year incidence of DR (OR:0.48;95%CI:0.33,0.71) and prevalence (OR:0.83;95%CI:0.77,0.89) and 5-year incidence of AMD (OR:0.996;95%CI:0.993,0.999) decreased, and prevalence (OR:1.35;95% CI:1.17,1.56) and 10-year incidence of OAG (OR:1.40;95%CI:1.22,1.61) increased with longer axial length. In all three studies, the association between higher OAG prevalence and longer axial length was nonlinear with a slight increase for the moderate myopia range, and a steep increase in the highly myopic range.Myopia is associated with a lower prevalence of DR, AMD and ACG and lower incidence of DR and AMD, while high myopia more than moderate myopia is associated with a higher prevalence and incidence of OAG. Future studies may assess whether in myopia, in particular in moderate myopia, the myopia-related advantages, i.e., lower prevalence of DR, AMD and ACG, may outweigh the increased risks for OAG and other myopia-related disorders.Copyright © 2024. Published by Elsevier Inc.