an uncorrected visual acuity of at least 20/40 (6/12) with both eyes open. 1 }5 o. U/ z& _- E. s$ ~visual aids (glasses or contact lenses) must have vision of 20:20 (6:6) with both eyes open. ! F; E; S, s( K, g3 h
9 s3 J) p2 ^5 B
请问上面的意思是什么?相当于国内什么等级的视力?谢谢!