Cillian Murphy's Oppenheimer costars kept getting lost in his 'ocean eyes' on set

Cillian Murphy's piercing blue eyes might be more powerful than a nuclear weapon.

According to the Irish actor's costars in Oppenheimer — the new Christopher Nolan drama about the American physicist who spearheaded the development of the atomic bomb during World War II — Murphy's peepers are so striking that they proved to be a distraction on set.

"It's a real problem when you're doing scene work with Cillian," Matt Damon, who plays Manhattan Project director Leslie Groves, told PEOPLE. "Sometimes you find yourself just swimming in his eyes."

Emily Blunt, who plays Oppenheimer's wife, Kitty, added, "It's like that 'Ocean Eyes' song by Billie Eilish. We just hum it all day."

Murphy protested, "They're not even that blue!"

Hogan Media/Shutterstock 'Oppenheimer' castmates Matt Damon, Emily Blunt, and Cillian Murphy

Oppenheimer marks Murphy's sixth film with Nolan, and the first in which he plays the lead role. Speaking to EW earlier this year about their shared cinematic history, Nolan revealed that it was Murphy's "crazy eyes" that initially drew him to the actor, leading to a collaborative relationship that began with the Dark Knight trilogy.

"I remember I was up in San Francisco writing Batman Begins and there was something in the San Francisco Chronicle about 28 Days Later," Nolan recalled. "I saw a picture of you with your shaved head and your crazy eyes — no offense. I remember being struck by your presence, literally from that one photograph, and then started to look into who you were, and what you'd done, and got very excited about the idea of meeting you, and having you screen-test for Batman."

That role went to Christian Bale, of course, but Nolan knew he wanted Murphy to take part and cast him as the villain Scarecrow. "Everybody was so excited by watching you perform that when I then said to them, 'Okay, Christian Bale is Batman, but what about Cillian to play Scarecrow?' there was no dissent," he said.

Melinda Sue Gordon/Universal Pictures Cillian Murphy in 'Oppenheimer'

When Nolan phoned Murphy and asked him to take on the role of J. Robert Oppenheimer, "It was kind of overwhelming," the actor admitted in a recent installment of EW's Around the Table video series, which was conducted prior to the actors' strike. "Chris' way of operating is that he just calls you out of the blue," Murphy explained. "I genuinely had no idea. He said he was making a movie about Oppenheimer and he said, 'I'd like you to play Oppenheimer.' I had to sit down."

Check out the video above for more from Murphy and his blue eyes. Oppenheimer is in theaters now.

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