Having a maximal visual acuity of the better eye, after correction by refractive lenses, of one - tenth normal vision or less(20 / 200or less on the Snellen test.

• 瞎的，失明的通过折射矫正后，最好眼最大视力敏感度为正常视力的1/10或少于1/10的（斯奈伦测试20/200）或更低