Abstract: Primary angle closure disease (PACD) has great variety of classifications and terminologies. The traditional classification of PACD based on clinical presentation,  is useful in allowing easy recognition of the type of management necessary,  but the definition is not clear. The classification developed by the International Society of Geographical and Epidemiological Ophthalmology (ISGEO) was  concise,  especially helpful in epidemiologic surveys, but could not be widely used by the clinician. A new classification proposed recently has amalgamated all the clinically subtypes of PACD into a staging, such as PACD suspect, PACD Ⅰ, PACD Ⅱ, PACD Ⅲ, and it is helpful for treatment.