E-learning’s usability measurement toward students with myopia visual impairment AG Pradnya Sidhawara, Djoko Budiyanto Setyohadi, Luciana Triani Dewi and Kusrohmaniah Sri E3S Web Conf., 73 (2018) 12004 Published online: 21 December 2018 DOI: 10.1051/e3sconf/20187312004