The screech of metal against wood was the moment I began to question the efficacy of miraculous-sounding contact lenses that correct impaired vision while you sleep.

• 听到金属碰擦木头的刺耳声时，我不禁怀疑这种隐形眼镜听起来不可思议的疗效：能在人睡觉时矫正近视。