Detailed Product Description 1.the memory capacity of systme≥ 160 the testing picture of vision.2.vision charts with international standard:word E, word C,digital, children. color-blind,astigmatism and ect. 3.measuring, distance 2.5m-5m (choose eighter)4.controlled by infrared5.operating voltage: AC 220v 50/60hz 20w 6.white and highlight field of screen:80-320cd/m 7.turn on time less than 5 ...