an uncorrected visual acuity of at least 20/40 (6/12) with both eyes open. & t4 I* B& \5 j
visual aids (glasses or contact lenses) must have vision of 20:20 (6:6) with both eyes open. / U. r# Y, F9 f7 X, q2 [5 ^
7 y- ~2 ^# { i4 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!