an uncorrected visual acuity of at least 20/40 (6/12) with both eyes open. ! I( \& T) t$ j7 I, Q9 u9 f
visual aids (glasses or contact lenses) must have vision of 20:20 (6:6) with both eyes open. " C/ m" `' Z0 U# X6 Y, w$ P9 }" [+ P( o% Y. q
请问上面的意思是什么?相当于国内什么等级的视力?谢谢!