Over the years, computer-generated imagery (CGI) has brought action and fantasy movies to life right in front of our eyes. Hollywood artists create realistic alien landscapes or otherworldly creatures that look like they could be from right here on planet Earth.

But CGI isn’t limited to creating monsters, aliens, and landscapes. With advances in technology, Hollywood has used CGI to reverse — and even fast forward — the aging process of your favorite stars. Take, for instance, these 10 actors who underwent a CGI facelift to change their ages (and saw mixed results)!

1. Jeff Bridges in Tron: Legacy (2010): He played both Kevin Flynn and CLU in the 1982 movie Tron: The Original Classic. So naturally, when the sequel was announced, Jeff Bridges, 60 at the time of release, was announced to be returning as his original character of Kevin Flynn.

Variety

Bridges was eager to get on set and begin filming. Since his character, CLU, has been stuck in the video game for 20 years, he hasn’t aged. Walt Disney Studios used CGI to make Bridges resemble his original appearance. Not too bad of a job.

Walt Disney Studios

2. Robert Downey Jr. in Captain America: Civil War (2016): Resuming his role as Iron Man in one of the Marvel’s Avengers movies, Downey, 51 at the time of release, battled it out with Captain America over political oversight for the superheroes. 

Walt Disney Studios

 In the movie, there is a flashback scene where Tony Stark revisits his past. Director Anthony Russo explained how they used CGI and months and months of filming to make the scene work. It’s hard to make a face look realistic, so that’s probably the reason it looks like young Tony Stark got a face lift.

Walt Disney Studios

3. Johnny Depp in Pirates of the Caribbean: Dean Men Tell No Tales (2017): One of the main characters in the Pirates of the Caribbean franchise movies, makes a return for the fifth installment. Deadly ghost sailors led by his old nemesis, Capt. Salazar, escape from the Devil’s Triangle with a vengeance for Depp’s character, 54-years-old at the time of release.

TMZ

The directors of the movie, Joachim Rønning and Espen Sandberg, spent a year working with the effects company Lola to portray Captain Jack Sparrow as his teenage self. The CGI was so believable that people thought production cast a Depp-lookalike when the whole time it was CGI.

Walt Disney Studios

4. Anthony Hopkins in Westworld (2016): He played Dr. Robert Ford in the HBO hit series. At the time of release, 78-year-old Hopkins played a character who was the co-creator of the Westworld park as well as the Park Director. He had a vision for the park with an unorthodox way of achieving it.

HBO

During the first season, the directors of Westworld showed its viewers a flashback of young Ford and his partner Arnold discussing the beginning stages of the theme park. Visual-effects supervisor Jay Worth explained how they used photos and videos of young Hopkins to make a 3D visual scan, which was then placed over the stand-in during post-production. Pretty believable.

HBO

5. Brad Pitt in The Curious Case of Benjamin Button (2008): Aged 44 at the time of release, Pitt played a character who aged backwards. Naturally, this meant they would need a little bit of help from computers! 

ET Online

 One of the first movies to utilize age altering visual affects, it’s quite impressive for its time. For Pitt to portray a young adult to middle-aged man, he just had to undergo makeup and prosthetic work. To play an old man and a baby, however, Paramount pictures applied CGI magic. Has there been better CGI work? Yes. Still, for 2008, it’s pretty impressive.

Paramount Pictures

6. Dwayne “The Rock” Johnson in Central Intelligence (2016): Kevin Hart and “The Rock” played classmates who reconnect at their high school reunion. Johnson, aged 44 at the time of release, played a CIA agent who needs Hart’s character’s accountant brain to help save a compromised U.S. spy satellite.

Movie Hole

“The Rock” also played the younger version of his character who was an overweight teen. Director of the film, Rawson Thurber, explained that they were able to use CGI and special effects to superimpose Johnson’s face onto the body of Vine star Sione Kelepi for the flashback scenes.

Warner Bros. Pictures

7. Arnold Schwarzenegger in Terminator Salvation (2009): He has been acting in this iconic franchise since 1984, so when the fourth installment was underway, he had to make a cameo appearance. He appeared as Prototype T-800, or also known as T-RIP.

Beretta/Sims/REX/Shutterstock

The production crew of Terminator Salvation didn’t even film with Schwarzenegger. They used digital makeup on the face of bodybuilder and actor Roland Kickinger to make it look like he had Schwarzenegger’s face.

Warner Bros. Pictures

8. Orlando Bloom in The Hobbit: The Desolation of Smaug (2013): In the prequel movie, Bloom was scheduled to appear as his Lord of the Rings character Legolas. The movie follows the journey of Bilbo Baggins and his companions as they travel to Lonely Mountain to face the dragon Smaug.

Telegraph

 Since the movie took place ten years earlier — and elves don’t age — Bloom needed to undergo a little bit of movie magic to look the part. Instead of using makeup to give the illusion of a younger appearance, Warner Bros. Pictures opted to use CGI instead.

Warner Bros. Pictures

9. Paul Reubens in Pee-wee’s Big Holiday (2016): Resuming his classic role from the 1980s, Reubens, aged 64 at the time of release, returned to the screen to experience his first ever vacation. Traveling across the country to attend a birthday party in New York city, Pee-wee never fails to get into some sort of hijinks. 

NBC

 Paul Reubens didn’t feel he looked young enough to play the role, so the production company used CGI and makeup to make him look more like 1988 Pee-wee. His wrinkles were removed, his laugh lines softened, and any excess skin was either taped down or digitally removed.

Pee-wee Pictures

10. Kurt Russell in Guardians of the Galaxy Vol. 2 (2017): Russell played the character Ego the Living Planet. Russell, aged 66 at the time of release, portrayed a celestial who was able to create an entire planet around him while still being able to hold “human” form.

Draft House

 The movie used a flashback sequence to show you his origin story. Although CGI was used, Russell wanted to use good old fashioned Hollywood magic so that CGI didn’t make him look fake. While filming, Russell had plenty of makeup on his face, and in post-production, the special effects team went in and did a little touch up work.

Walt Disney Studios