Disclosure - When to tell your employer?

Hey everyone, I have to say i havent been as active on here as I wanted but I am here to remedy that. I am one of the reporters and I was also recently interviewed as part of the MS & Work Reporters series, you can see the videos on the Shift.MS facebook and website. One of the videos tackles the question of disclosure, probably one of the most common questions I am asked on my MS&Work facebook group and one which is so hard to answer. Here is the video discussing this point: https://www.youtube.com/watch?v=12uHlrrd6CQ&t=36s What is your experience of this?