an uncorrected visual acuity of at least 20/40 (6/12) with both eyes open. - \6 }: U2 W7 R% l+ @" q
visual aids (glasses or contact lenses) must have vision of 20:20 (6:6) with both eyes open. $ R7 ]/ e6 q. d! M
: `2 d" n$ l. z, o+ {4 C0 p
请问上面的意思是什么?相当于国内什么等级的视力?谢谢!