Anki 2.1 was released 3 weeks ago, and is the current stable release. It depends on newer versions of QT. It might work better than the one from apt.
If you really want to install the one from apt, e.g. because your favourite plugins haven't been updated to work with 2.1, then perhaps this approach will be easier than re-installing the OS:
Thank you rahimnathwani. The procedure took a while to complete, and I'm getting some warnings, but the procedure from https://github.com/gnprice/anki-jessie worked. This should hold me until Anki version 2.1 becomes available for Raspbian stretch.
If you really want to install the one from apt, e.g. because your favourite plugins haven't been updated to work with 2.1, then perhaps this approach will be easier than re-installing the OS:
https://github.com/gnprice/anki-jessie