History is full of other examples of successful people with disabilities.(I understand this sentence,but the next I no)Some famous musicians have had little or no sight.(what does it meanthe "have had ")

History is full of other examples of successful people with disabilities.(I understand this sentence,but the next I no)Some famous musicians have had little or no sight.(what does it meanthe "have had ")

历史上成功人士带有残疾的例子比比皆是。有些著名的音乐家就是弱视或者盲的。

have had是完成时态，建议找本语法书看看。

I don't understand either.

I seem to understand,the" little"and "no"是并列关系。