an uncorrected visual acuity of at least 20/40 (6/12) with both eyes open. 2 C, j6 B" n! a4 L6 T, B O3 _
visual aids (glasses or contact lenses) must have vision of 20:20 (6:6) with both eyes open. 1 v- A% c: n2 m, h% [; g( ~) @" N) `4 t6 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!