In this Spanish-language edition of Vision, a young blind activist shares how she became a leader for the disabled community.Ever since Precious Perez was a child, she has loved to sing. Her family always praised her singing, saying she could even attend Berklee College of Music one day—planting a seed that would become her dream.Precious was born two-and-a-half months premature and weighed just one pound. Her eyes did not develop fully, and she is...