What is the reality for a child with undetected vision impairments, such as amblyopia (lazy eye), strabismus (crossed-eyes), or severe nearsightedness or farsightedness?

• 如果一个孩子患上了未觉察到的视力缺陷，诸如弱视，斜视或严重的近视或远视，会有什么后果呢？