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ISO 8596:2017
Ophthalmic optics - Visual acuity testing - Standard and clinical optotypes and their presentation
ISO 8596:2017 specifies a range of Landolt ring optotypes and describes a method for measuring distance visual acuity under photopic conditions for the purposes of certification or licensing.
ISO 8596:2017 is neither intended as a standard for clinical measurements nor for the certification of blindness or partial sight.
Other optotypes used for clinical investigations are described in Annex A for information.
International Organization for Standardization [iso]