Sandra Bullock on how tough it was to act blindfolded in Bird Box

In the post-apocalyptic world of the new Netflix film Bird Box, there is a monster that embodies people's worst fears, causing them to commit suicide. The only thing that heralds its arrival are squawking birds.

Those who are possessed manifest glowing eyes then kill themselves with the nearest weapon.

Survival is possible only by blindfolding oneself outdoors. That is what Sandra Bullock's character has to do as she tries to escape with two children to safety through a forest and down a river in a rowboat.

Based on the 2014 novel of the same name by Josh Malerman and directed by Danish auteur Susanne Bier, Bird Box premieres on Netflix on Dec 21 and is said to be a vision-centric version of the hit horror flick A Quiet Place starring Emily Blunt and John Krasinski.

At our interview at the Four Seasons hotel in Beverly Hills, Bullocksaid the river scenes were not the worst part of the shoot, as the cast were "protected and crew members were around us at all times".

"The hardest part was being brutal to two little faces... beautiful, innocent faces... I had to be incredibly tough on them. But at the river, we felt safe."

There were four or five doubles for the children to accommodate strict schedules for child actors.

"Sometimes there were no kids, and half the scenes were me acting to a matte box or to a cameraman with an X on his head," she said.

Acting was harder without sight.

The 54-year-old US actress said: "You realise one of your tools for acting is completely taken away, and how much I relied on my eyes to tell a story in film. Which made me angry and frustrated and fearful that I wouldn't be able to pull off a scene and give Susanne what she needed.

"But every time I got whipped up into a frenzy, I just took that and piled it on top of the day and let it affect the work, because that was what you would feel in the moment."

Nothing was choreographed and the Steadicam operator just followed her into the scenes.

"They said, 'This is where you can go,' and I remembered where the trees were and I knew where the steps were, but then I would change it and he would follow. I hit the camera two or three times. My concern was, as an actor, am I going to be able to pull off emotionally what I wanted to pull off? But Susanne knew how to get me out of my comfort zone and make me do it."

When it comes to being outdoors with the two African-American children she adopted - Louis, eight, and Laila, five - Bullock has a different challenge. Namely, the paparazzi.

"My kids are pretty good. I scared them so much about being in public that they stay close. I always have to remind them that nothing is going to happen and keep your head down and keep walking.

PROTECT

"I try to keep my kids' faces out of the public eye as much as possible, so usually you see a big hand covering up the child's face... I think eventually I will loosen up and just let them fend for themselves," she said.

There are other important discussions the self-confessed "overly protective" single mum has with them.

"I have to have conversations with them that millions of other parents have because of the colour of their skin, because I know they have got the added pressure of that. I am sure I am failing in some regard somewhere, but to be a parent is to fail."

Bullock said she was a handful growing up and gave her "incredibly strict" German mother a hard time.

"I was a child who questioned authority a lot and was a smart alec. Now I have an amazing daughter that does the same thing to me. She is me times a thousand. My mother is laughing at this point. She always said, 'Wait until you have daughters.'"

Bullock herself gets "extreme anxiety when it comes to red carpets".

"I am not a good public figure. I don't like it. I don't feel in my element. I get crabby and irritated. I get sweaty palms, I basically unravel. So I wear something that is like a suit of armour that feels like me, and it says what I want to say.

"If you look at all my pictures on the red carpet, I look exactly the same - a deer in headlights. I have one look and that is it. I go out and freeze and I am like, 'Take the f****** picture and let me get inside.' But I do enjoy fashion. I just wish I didn't have to do it on a red carpet."

The writer is the president of the Hollywood Foreign Press Association, a non-profit organisation of entertainment journalists that also organises the annual Golden Globe Awards.