It might be easy to dismiss Sarah Polley's "Away from Her" as an "old people's movie" - the film, after all, tells the story of an aging couple whose 45-year marriage is torn apart by Alzheimer's disease.

But that would be a misguided folly on the part of any movie lover, because "Away from Her," Polley's feature-film directorial debut, is an astoundingly accomplished film, a moving look at enduring love that will resonate with young and old, cynic and romantic.

Stunningly shot in the middle of a rural Ontario winter, the film stars reclusive British actress Julie Christie as Fiona, a woman whose forgetfulness turns to something far more serious, in a rare silver screen appearance that resulted in months of cajoling by Polley. Canadian acting legend Gordon Pinsent plays Fiona's husband, Grant, with a gracious and dignified despair that matches the quiet restraint of the film.

After Fiona goes cross-country skiing on a frozen lake at the couple's cottage and gets lost, she insists on going to a nursing home. A reluctant Grant is forced to leave his wife in a care facility and stay away for 30 days while she becomes accustomed to her new surroundings.

When he's finally allowed to see her again, Fiona has all but forgotten him in favour of another man, a fellow patient in the facility played by Canadian actor Michael Murphy.

"He doesn't confuse me," Fiona says when Grant attempts to cut through the fog of Alzheimer's and figure out is going on between his wife and Aubrey. "He doesn't confuse me at all."

The message is clear, in Grant's mind: once a philanderer, he fears his wife is now, many years later, trying to get back at him as her mind starts to falter and she's no longer able to neatly compartmentalize the pain his actions caused her earlier in their marriage.

And so, when Fiona falls into a life-threatening depression after her boyfriend's departure from the facility, Grant does what he can to save her at the risk of his own happiness.

Rarely has an elderly onscreen couple been more physically and intellectually attractive than Grant and Fiona - Christie's Fiona, with her thick white tresses and sly smile, emanates all the beauty and wry wit that clearly still captivates her husband, and Pinsent, with his grey beard, cable-knit sweaters and gravelly baritone, is an undeniably sexy leading man three years before his 80th birthday.

It's Pinsent, in fact, who steals the movie. With skilful reserve, he's wonderful in every scene he's in, his brilliant blue eyes conveying pain and dismay despite his outward stoicism. His turn here truly is worthy of major award recognition.

It's no wonder the film has wowed critics at the Toronto, Sundance and Berlin film festivals. Polley's script is masterful - she adapted it herself from an Alice Munro short story - and filled with memorable moments between Pinsent and Christie, particularly a scene where Fiona praises Grant for at least having the maturity not to have left her for one of his young lovers.

"I think people are too demanding," she tells Grant as he drives her to her new home. "People want to be in love every single day. What a liability!"

Polley has also peppered the film with Canadian references: Fiona and Grant hike Ontario's Bruce Trail, they slow-dance to Neil Young's "Harvest Moon" and a patient at the care facility, a former commentator for the Winnipeg Jets, is seen eagerly providing the play-by-play to his friends at the clinic as they regularly take in NHL games.

But what's most profound about "Away from Her" is how realistically it portrays a long marriage and what happens after many years together, some of them unhappy. While Grant hurt Fiona in the past, his love for her, in the end, is grandly selfless.

Far more than a movie about Alzheimer's disease, "Away from Her" is in fact about the true meaning of lasting love, how it soars and how it stumbles, and what people are willing to sacrifice for it.

"I never wanted to be away from her," Grant recalls early in the film as he recalls why he decided to marry Fiona. With Polley's deft and delicate handling, we watch Grant, lonely and hurt, cast aside what he wants at the end of their long life together to prove just how sincerely he's loved her.

Three and a half stars out of four.