How will the Visualforce page will stop working on Lightning UI in Salesforce?

Hi,

Lightning Experience brings an all new user interface to your Salesforce organization, but that doesn’t mean your Visualforce apps stop working. Visualforce pages work in Lightning Experience, many without any revisions. Things have moved around, though, and there are some chores you’ll want to complete to make sure your Visualforce pages work the way you expect as your users switch between Lightning Experience and Salesforce Classic. And there are a very few features that, alas, don’t work in Lightning Experience.