an uncorrected visual acuity of at least 20/40 (6/12) with both eyes open. 1 H( H* F7 G' f% ` r& a7 b
visual aids (glasses or contact lenses) must have vision of 20:20 (6:6) with both eyes open. ; P$ M( N3 B+ f m, {1 [
2 y+ c/ d) }# ?: u* E3 G+ f
请问上面的意思是什么?相当于国内什么等级的视力?谢谢!