1. Visual Impairment and Blindness Fact Sheet,2018
2. Global Prevalence of Blindness and Distance and Near Vision Impairment in 2020: Progress towards the Vision 2020 targets and what the future holds;Bourne;Investig. Ophthalmol. Vis. Sci.,2020
3. Apple VoiceOverwww.apple.com/accessibility/voiceover/
4. JAWSwww.freedomscientific.com
5. WebAim: Screen Reader User Survey #5 Resultshttp://webaim.org/projects/screenreadersurvey5/