an uncorrected visual acuity of at least 20/40 (6/12) with both eyes open. * `3 W) p2 R* `& Z& n
visual aids (glasses or contact lenses) must have vision of 20:20 (6:6) with both eyes open. 9 I: [( y; @6 j
- |- U' `5 c0 c+ D+ Q$ j" z
请问上面的意思是什么?相当于国内什么等级的视力?谢谢!