Ophthalmic optics. Visual acuity testing. Standard and clinical optotypes and their presentation Ingestion-build-105964 EN 438‑4 [2]

EN 438‑4 [2]

ISO 8659 aids in establishing certain basic requirements for the endurance testing of plastics valves to ensure that uniform test methods are adopted

or rollers and loose load trailers intended to be used for the transportation of baggage and cargo in airports

N-sulfocarbamoyl-gonyautoxin 1 and 2 (C1

except where guidance is given as to dealing with spillages

Ophthalmic optics. Visual acuity testing. Standard and clinical optotypes and their presentation Ingestion-build-105964 EN 438‑4 [2]1 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.