[4] Following a brutal attack in a parking lot, violinist Ellen Ashland wakes up in hospital to learn that she has been blinded.

Clayton, a nurse her brother has hired, arrives to care for her as she begins to adjust to life without sight.

Lana reacts by whispering "trust no one," and then flees Ellen's apartment upon the arrival of her abusive husband, Russo.

At first she thinks it's Lana and begins to apologize to her for the misunderstanding, but it’s Russo, who warns her to stay away from his wife, and says he will be talking to the building management about her.

Hearing someone enter the apartment, Ellen thinks that Clayton has returned and begins to apologize.

Hearing the assailant’s breathing pattern she recognises it as that of the person who attacked her in the parking lot.

She quickly realises the apartment she was staying in was fake, and all of the noises "outside" were coming from a speaker system.

Clayton then arrives to cook Ellen dinner and knocks twice; at that moment she realises all of the people she has interacted with since her attack - the doctors, the detective, the paramedic, Russo - were all Clayton playing different roles, but giving himself away by his habit of knocking on any surface twice.

Six months later, Ellen prepares to go on stage to the sound of an elated crowd, as an assistant asks her if she needs any help.

[7] Johnny Loftus from Decider was more positive, and compared the film and its ending to Wait Until Dark (1967) and Shutter Island (2010), and recommended readers to watch it online.

[8] Writing for the Australian Broadcasting Corporation, a journalist gave the film three stars and a half out of five, and said that "Sightless ticks the boxes for [...] an over-the-top thriller that is not afraid to ramp things up to eleven, its manic climax just one of its many enjoyable charms.