Tom Hopper Reveals the ‘Magnificent’ Reaction His Son, 10, Had to Seeing Times Square for the First Time (Exclusive)

Tom Hopper says his son Freddie can light up any place — even one as bright and bustling as New York City!

The Umbrella Academy star, 40, reflected on the joy of seeing his 10-year-old — whom he describes as his “little ray of sunshine” — take in the sights of the Big Apple for the first time during a recent visit.

“We [were] just here in New York, and what’s so beautiful about Fred is, he sees — he lives so much in the present and then something kind of takes him and affects his emotions,” Hopper tells PEOPLE at the N.Y.C. red carpet premiere of The Terminal List: Dark Wolf on Aug. 4.

“When he saw Times Square, and he sees this massive city — we live in like rural England, right? So we’re surrounded by fields and animals and stuff. So, when he comes to something like this the way his brain works, it’s so magnificent. He’s just so excited, and his eyes light up and he’s laughing and screaming,” Hopper recalls.

Freddie — whom the actor shares with his wife, actress Laura Hopper — was diagnosed with autism just before his 5th birthday. Since then, Hopper and his wife have openly shared their journey of raising their son in the hopes of supporting other parents who are navigating similar paths.

He and Laura also share a 7-year-old daughter named Truly Rose, whom he said has been very supportive of her elder brother. Hopper shared how thankful he was to have her presence by Freddie’s side.

“My daughter is a phenomenal little sister to him, you know, she’s like the perfect [sibling]. We couldn’t have asked for a better little sister for Freddie,” Hopper says. “She’s just such a beautiful little soul. She’s amazing.”

The Game of Thrones alum celebrated Freddie’s 10th birthday in an Instagram post on June 1 alongside a photo of him and his son holding his hand as they appeared to take a stroll in a grassy area near a pond. 

“Today my beautiful, special little boy Freddie Hopper turns 10! Happy Birthday my little ray of sunshine. You light up my world every day ☀️,” the actor captioned the photo.

Hopper previously opened up to PEOPLE in 2020 about how he and his wife have changed their approach to parenting since Freddie’s diagnosis. They noted that after doing some research into autism and education courses, they realized each child with autism is unique and should be understood and supported in ways that honor their individual needs and strengths.

Never miss a story — sign up for PEOPLE’s free daily newsletter to stay up-to-date on the best of what PEOPLE has to offer​​, from celebrity news to compelling human interest stories.

“The biggest thing for us was learning Freddie,” he said at the time. “We’ve had to figure out what works for him and what doesn’t.”

“You have to trust each other and the journey,” he added. “The right things will happen eventually, but it doesn’t happen overnight. My son has autism, and he amazes me every day. His brain just works in a different way.”