1. Figure I Blindness prevalence by age,1991
2. Data on blindness prevalence and causes throughout the world;Maitchouk, I.F.,1981
3. Epidemiology of blindness and visual impairment in Vanuatu;Newland, H.S.; Harris, M.F.; Iwasaki, W.; Momomura, K.; Walland, M.; McKnight, D.; etal;Bull WHO,1992
4. Brilliant LB, Pokhrel RP, Grasset NC, Lepkowski JM, Kolstad A, Hawks W, et al. Epidemiology of blindness in Nepal. Bull WHO 1985; 63: 375-86.
5. Prevalence et causes de la cecite Congo;Negrel, A.D.; Massemba-Yako, B.; Botaka, E.; Minassian, D.C.; Coddy-Zitsamate, R.;Bull WHO,1990