Measurement of visual acuity with a digital eye chart: optotypes, presentation modalities and repeatability Giada Campo Dall¿Orto; Alessio Facchin; Alessia Bellatorre; Silvio Maffioletti; Marina Serio;

Quantification of visual acuity: ¿Counting fingers¿ and ¿Hand movement¿ with the Berkeley Rudimentary Vision Test Alba Herrero; Halima Berrada; Rafael I. Barraquer; Ralph Michael;

Prevalence of astigmatism among 99,515 children in different areas of Xi'an City, China Ye Zhang; Xiaokang He; Wei Dong; Zihao Wang; Chengfei Liu; Yanying Li; Zhaojiang Du;