This Post-Authorization Safety Study (PASS) is intended to fulfill a regulatory post-marketing requirement to provide data regarding visual abilities in children taking azithromycin (immediate-release formulation) for acute pharyngitis/tonsillitis. The primary objective of the study is to examine the incidence of clinically significant worsening in any of the following ophthalmic exams: best corrected visual acuity (distance), color vision, Amsler grid testing, anterior segment biomicroscopy, and fundus examination, in a group of approximately 30 pediatric patients taking azithromycin oral solution for treatment of an authorized indication of use (pharyngitis/ tonsillitis).