People losing sight in one eye cannot do binocular disparity processing. It means they cannot perceive the sense of distance from the binocular disparity, which makes grasping an object or sewing clothes difficult. It can significantly reduce the quality of life.
The number of visually impaired patients is 285 million, which includes 246 million people of poor vision and 39 million people of blindness [Pascolini and Mariotti 2010]. The number of people losing sight in one eye is not published, however it is considered to be the same order to that of the visually impaired patients.