Does the Anchor Text has to be unique?

[Kerry_Watson2]

Does the Anchor Text has to be unique? In order to get real link juice out of the host page. Because from what I am seeing many links which have same or similar anchor texts are tend to rank lower in the results.

The link wording should be unique among all of the links on the page, or the link's unique function should be able to be deduced from the context of the link. This aids in determining a link's function and distinguishing it from other similar links.