Many such things my eye has seen, and my ear has heard things more striking than these: Almost surely ben Sira is injecting his own personal experience into the discussion here. It is hard to avoid the impression that when he wrote verses 1-3 he had some particular family or families in mind. My eye has seen refers not necessarily to things he has literally seen, but to situations he has experienced, known, lived through. Good News Translation provides a good model for the verse, but another possible rendering is:

• I know personally of many such situations, and have heard of even more striking [or, important] cases.

Quoted with permission from Bullard, Roger A. and Hatton, Howard A. A Handbook on Sirach. (UBS Helps for Translators). New York: UBS, 2008. For this and other handbooks for translators see here.