an uncorrected visual acuity of at least 20/40 (6/12) with both eyes open. ) V. j1 j1 c( _! K y6 o0 t1 m* b
visual aids (glasses or contact lenses) must have vision of 20:20 (6:6) with both eyes open. 5 _/ \5 h7 _* P: K9 @8 X5 z' D0 F+ A/ ?1 _6 d$ d
请问上面的意思是什么?相当于国内什么等级的视力?谢谢!