an uncorrected visual acuity of at least 20/40 (6/12) with both eyes open. , J! j4 l& L4 N% o$ D6 R( w" v
visual aids (glasses or contact lenses) must have vision of 20:20 (6:6) with both eyes open. * ^6 |9 W+ r% a$ b
- l# [$ U8 U. B0 W6 r
请问上面的意思是什么?相当于国内什么等级的视力?谢谢!