an uncorrected visual acuity of at least 20/40 (6/12) with both eyes open. / m! e9 F5 J. k0 Z9 u% J4 n" c
visual aids (glasses or contact lenses) must have vision of 20:20 (6:6) with both eyes open. - V7 Q# J$ U0 R: g2 @+ `5 E/ A; y# u
请问上面的意思是什么?相当于国内什么等级的视力?谢谢!