International Journal of Ophthalmology is an open access journal under a  Creative Commons Attribution (CC BY NC ND) license, per the publisher policy at http://www.ijo.cn/gjyken/ch/first_menu.aspx?parent_id=20120104164955001.
Except where otherwise noted, this item's license is described as International Journal of Ophthalmology is an open access journal under a Creative Commons Attribution (CC BY NC ND) license, per the publisher policy at http://www.ijo.cn/gjyken/ch/first_menu.aspx?parent_id=20120104164955001.