ISO 24509:2019 pdf download – Ergonomics — Accessible design — A method for estimating minimum legible font size for people at any age. 1 Scope This document provides a method for estimating minimum legible font size for single characters, but not for words or sentences, in self-luminous or reflected mode, used in documents, products labels, signs, and displays for people at any age and in any viewing condition in which viewing distance, luminance and contrast are varied. This document applies designing and evaluating legibility of single characters for people at any age who have no pathological disorders in their eyes,...