Jay Leno Opens Up About Being His Wife's Caretaker as She Battles Dementia

Jay Leno's really taken his "in sickness and in health" wedding vow to heart, serving as his wife Mavis' caretaker throughout her battle with dementia.

The former late-night TV talk show host opened up about his spouse's health issues in an interview with Today Thursday, and he was honest about how brutal dementia can be -- specifically citing a three-year period when Mavis woke up every day thinking someone had called to tell her her mother had died.

Jay -- who tied the knot with Mavis in 1980 -- admitted the period was "really tricky" and spoke about other areas of their lives that became restricted by her disease ... including their ability to travel, which they've replaced with watching travel videos on YouTube.

Still, Jay said Mavis -- whose dementia diagnosis was publicly revealed last year -- still recognizes him and hasn't forgotten him, and he said his wife is "extremely comfortable" under his care.

Jay said Mavis is reliant on him for help, which isn't a big deal for him ... he said he enjoys being her caretaker.

The comedian said they've developed a routine ... he picks her up and carries her to their bedroom every night, which Mavis really gets a kick out of.