This chart is designed for vision testing at 3m and has a visual acuity range of 10/50 to 10/8 (20/100 to 20/16 equiv). Eye chart measures 23 X 35.5 cm and can be wall mounted or used with our SDT-399-LSV Illuminated Cabinet. This House, Apple, Umbrella vision test is made of high impact polystyrene and is portable. It is a non-reflective eye chart that can be used to aid school nurses in vision screening of young children. This style of symbol vision test is often used as an acuity and amblyopia screener in preliterate patients.