By Edwin Sim
•
May 23, 2025
Visually impaired people (VIP) encounter difficulties with perception of environments in everyday life. A door on a wall or a column on a station might be easily detected and seen, but it is an invisible hazard for VIP. With this in mind, Contrast therefore is an essential and vital tool for VIP to navigate in this world (Bright et al; 1997, Dalke et al; 2004). There are five key factors, according to Dalke and Conduit; 2010, which affect visual acuity (including contrast), for assessing the visibility of designs in a real world context. The colour contrast assessment model, developed by Dalke and Conduit enables designers, builders, consultants, developers to predict before and after installation whether a VIP is able to see an object, text or element of a building component. As outlined in AS1428.1 (2009) and AS 1428.4.1 (2009), contrast measurement is vital in building guidelines for design of environments and services for VIP. Therein the standards, the Light Reflectance Value (LRV) measurement must be measured using either a colourimter or a spectrophotometer with diffused illumination using Illuminant D65. LRV is measured through the visible colour spectrum, which is beyond what can be distinguished by the human eye alone. Measurement of LRV refers to both colour and appearance of the sample and uses geometric principles that relate to additional attributes such as gloss or shine. Spectrophotometers that are used to measure these characteristics typically utilises: Diffuse d/8° Sphere, specular reflectance included Diffuse d/8° Sphere, specular reflectance excluded In addition, the instrument has to be capable of measuring CIE for Yxy colour space. The measured LRV is defined by the tristimulus value Y. The chromaticity coordinates x and y provide an indication of the colour. LRV – A life saving tool. Speak with us on how you could assess and map your “good colour contrast” roadmap. X-Rite in Australia and New Zealand. Colouring the world with Novasys Group since 2018.
