an uncorrected visual acuity of at least 20/40 (6/12) with both eyes open. , X& i5 F$ o! ?1 t% _* n, u
visual aids (glasses or contact lenses) must have vision of 20:20 (6:6) with both eyes open. " a4 p$ P0 k6 E; w* H
! [2 r( X9 @; v9 x) d) I3 K
请问上面的意思是什么?相当于国内什么等级的视力?谢谢!