Every year, the media awaits with bated breath to see what fabulous gowns the celebrities will be wearing on the red carpet at the prestigious Met Gala.

This year’s theme was 'fashion in the age of technology', to coincide with the Costume Institute’s blockbuster exhibition, Manus x Machina: Fashion in an Age of Technology.

And there was one person who really addressed the theme perfectly and stole the show: Claire Danes.

Arriving in what appeared to be a classic princess-style gown, it wasn’t until she went indoors under darkness that the true magic of her dress was revealed.

See all the looks from the Met Gala red carpet

The frock - designed for the actor by American designer and Danes’ close friend, Zac Posen - appeared to glow in the dark and transformed the star into a real-life Cinderella.

Now, the designer has revealed exactly how much work went into creating the masterpiece.

Speaking to Good Morning America, Posen explained that the look was created by LED lights sewed into the lining, powered by 30 battery packs. The designer says the effect was created by the way the light travels, saying:

“You’re looking at light travelling vertically.”

Made from custom-made Gossamer imported from France, the dress took six people 600 hours to create.

Despite the amount of technology involved, the designer says it wasn’t as heavy as you might expect- thanks to its construction and light fabric:

“The dress is hollow inside,” explains Posen. “It’s as light as possible.”

The theme of the ball appealed directly to the designer, who says:

“I’m interested in that place, where the past and future meet, because that’s universal and that hits a chord around the world to women and girls and men,

“Just recognising beauty and a magic moment and fantasy and technology.”

Just like in the fairy tale, Danes’ dress was delivered to the atelier by a midnight curfew – Posen tells Entertainment Weekly.

“Clare was our Cinderella,” he says.

“I like to make people dream, that’s my job.”