The Facebook CEO - who has three-year-old Maxima and 12-month-old August with the 34-year-old paediatrician - knows how hard it is to get plenty of shut-eye when you have two young children and so he has invented the wooden light box to help her stay in bed for longer, which works by sending out a "faint light" between 6am and 7am to signal that it is time to wake up and see to their kids.
Alongside the contraction, he wrote on his Facebook page: "Being a mom is hard, and since we've had kids Priscilla has had a hard time sleeping through the night. She'll wake up and check the time on her phone to see if the kids might wake up soon, but then knowing the time stresses her out and she can't fall back asleep. So I worked on building her what I call the "sleep box". It sits on her nightstand, and between the hours of 6-7am it emits a very faint light - visible enough that if she sees it she'll know it's an okay time for one of us to get the kids, but faint enough that the light won't wake her up if she's still sleeping. And since it doesn't show the time, if she wakes up in the middle of the night, she knows to just go back to sleep without having to worry about what time it is."
Mark says that it has been a success and gushed that it was his way of showing his "love and gratitude" for his spouse.
He's also hopeful that an entrepreneur will pick up on the idea to make it a business.
He continued: "So far this has worked better than I expected and she can now sleep through the night.
As an engineer, building a device to help my partner sleep better is one of the best ways I can think of to express my love and gratitude. A bunch of my friends have told me they'd want something like this, so I'm putting this out there in case another entrepreneur wants to run with this and build sleep boxes for more people!"