How to make appearance of indexed terms link back to their index entry? [duplicate]

With an index named `foo`, we make an index entry using:

``````\index[foo]{\uplanop{#1}}
``````

although typically I use something like:

``````\newcommand{\Foo}[1]{{#1}\index[foo]{#1}}
``````

and with `hyperref` used as well, I get nice links back from my index. However, the terms' appearances in the text do not link to their index entries, so I can't quickly find out which other entries refer to Foo. Is there a way to change `Foo` so as to create such a link?