an uncorrected visual acuity of at least 20/40 (6/12) with both eyes open. % i. p, K" Y" R0 v8 V/ Y5 [, E+ [: B
visual aids (glasses or contact lenses) must have vision of 20:20 (6:6) with both eyes open. . c$ R- c$ t# p" U! L1 K$ S2 M$ i. L0 e$ v+ s- X; M9 l
请问上面的意思是什么?相当于国内什么等级的视力?谢谢!