eye-opener
eyeopener informal

Some said that the very writing of the case was an eye opener.

I check it daily and its been quite an eye opener.

These comments have been a real eye opener for me.

The events were an eye opener for the government and troops, who had thought that the war could be won very easily.

For me that such a site existed was a bit of an eye opener.

That performance was an eye opener, and money poured in.

I think this will be an eye opener for her.

The statement she made to the press became an eye opener for many people that the problem exists.

"Let's just say they were quite an eye opener," she said.

"The psychology of this was a real eye opener, not that I would back down," she said.