Ophthalmic optics. Visual acuity testing. Standard and clinical optotypes and their presentation Ingestion-build-105964 staple-fibre yarns

staple-fibre yarns

Evaluation of the business case has been expanded along with a new clause on defined engagement strategy

Note: Each abbreviation introduced here is explained in the text the first time it appears

EN 438‑4 [2]

due to national regulations

Ophthalmic optics. Visual acuity testing. Standard and clinical optotypes and their presentation Ingestion-build-105964 staple-fibre yarns1 Scope This document 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. This document 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.