Carey Mulligan has opened up about her grandmother's struggle with dementia - admitting the illness robbed her of the person she loved.

Carey Mulligan

Carey Mulligan

The 31-year-old actress is an ambassador for the Alzheimer's Society's Global Dementia Friends charity which strives to help make communities more dementia friendly, something which she feels strongly about since her grandmother was diagnosed with the degenerative disorder when Carey was just 16.

Dementia is a loose term used to describe different forms of the disorder that triggers a gradual loss of brain function. Alzheimer's is the most common strain of dementia, and as of yet there is no cure.

Speaking to The Daily Telegraph newspaper about her grandparent's struggle, the 'Suffragette' star said: "Piece by piece it felt like Nans was being taken from us. As I reached my early 20s, dementia was shutting down parts of her that made us feel like we were completely losing the grandmother that we loved so dearly."

Now, Carey has said that her grandmother rarely speaks at all, but says that she can communicate her feelings via her body language.

She said: "Today, Nans rarely communicates verbally and most of the time her eyes are closed. Her body language is good and tells us clearly whether she is happy or distressed and whether she wants something or not. In spite of this, sometimes it feels like she's not there any more and that we just can't reach her - and those are always the hardest visits."

Carey - who has 12-month-old daughter Evelyn with Mumford and Sons musician Marcus Mumford - works with the Alzheimer's Society's Global Dementia Friends charity because she says she now has the ability to see the world through the eyes of someone living with this disorder, and wants to help build a more compassionate society.

Wednesday (21.09.16) marks World Alzheimer's Day, a day in which organisations around the world concentrate their efforts on raising awareness for the disorder. For Carey, it is a chance to "inspire change".

She said: "I've been asked many times what being a Dementia Friend means to me. World Alzheimer's Day seems like a good chance to spell it out. It means living in a society where we are dementia aware. I want to inspire change the world over, as well as on our doorstep."