Karen Gillan and Brenton Thwaites star in "Oculus."

Phrases like “I see dead people” are embedded deeply in cultural imagination by now, but the “you’re seeing things” premise is getting a little old in horror. The ghosts almost always turn out to be real, and even if they’re not, the illusion is nearly always limited to them. But in Mike Flanagan’s new film, “Oculus,” the illusion is all around you. You can no more trust the reality of the ghosts than that of a shattered bowl or an apple.

{shortcode-531129bdb42c0bf10f024003ad0addf733401e23}

“Oculus” straddles the childhood and adult experiences of Kaylie (Karen Gillan) and Tim (Brenton Thwaites) with an antique, sinister mirror called the Lasser Glass. Recently released from the mental institution where he has spent the better part of his youth, Tom struggles to understand the role that the mirror played in his father’s grisly murder of his mother years ago. When Kaylie recruits him to help her document the mirror’s supernatural powers on camera, the siblings must come to grips with the reality that memory and technology may be no match for the glass.

Despite its ultimately predictable plotline, “Oculus” intelligently engages with the intersection of sight and technology as a fresh contribution to the horror genre. Considering its place in a genre that is experiencing a booming renaissance, “Oculus” is a standout mainly thanks to its sheer originality.

One of the film’s best accomplishments is its technique of overlapping flashbacks with contemporary action. Notoriously hard to get away with, the combination of flashbacks with the present are fluidly presented in this film. It seems clear that Flanagan and his writing partner, Jeff Howard, took the idea of a sibling rematch against their ghosts and pushed it further in the best way, cleverly making the most of the overlap between the children and their adult selves.

Even the film’s brief flashes of horrific images are ones we haven’t seen before—granted, it is clearly drawing on conventions set down by films like “Psycho,” but the attention paid to sights and sounds, light and space, indicates a fresh look at tropes of which there has been little retooling.

It is this kind of sharp reinvention that defines the triumph of “Oculus”—it is indeed hard to believe that Flanagan can display such a rich awareness of the genre while simultaneously kneading it into new shapes and patterns.

But the film’s particular success lies in its firm grasp on the intersection of vision, cameras, and reflections. For Kaylie, cameras are both a perfect tool for documentation and a means by which to check one’s sense of reality and illusion. But as the power of sight becomes increasingly destabilized over the course of the film, so too does technology, and one’s reflection, like a camera image, is transformed into a three-dimensional space with depth.