LilyMop, I have had to do this numerous times and as long as I am clear in the request and do it by the book, there hasn't been much of an issue. It's always a challenge because you need to disclose. You also have to remember that you're requesting a reasonable accommodation and in such, it's a negotiation and your employer will want to know what the accommodation for, and if the accommodation you propose to address the disability doesn't work for them, they may suggest something else. Go into it with the desire to solve the problem. So what is the health issue and how will working one day from home help with it, and how will it not be a problem for the employer? They want to make sure it doesn't disrupt business. So what checks and balances will you use to make sure the 1 day remotely working is productive and useful to them?

If you lay out very clearly how you will keep in touch during the day, when you will take breaks when working from home, and are very clear about the expectations on both sides of it, this can be a reasonable process.