The husband of American photographer and writer Judith Fox - Dr Ed Ackell - was told he had Alzheimer's Disease in 1998, three years into the couple's marriage.
Since then, Judith has watched Ed - a man who used to perform surgery and fly planes - forget how to do everyday tasks, such as make a cup of coffee or use the telephone. While caring for him at their home in California, she took photographs to capture his gradual decline.
These images - first published in Judith's book 'I Still Do' - are now being displayed in central London.
Take a look, as Judith tells her story.
BBC News - Audio slideshow: Loving and living with Alzheimer's