LONDON — Elton John says he struggled to watch his new musical because he has lost his eyesight after contracting an infection.

The singer-songwriter attended the opening night of “The Devil Wears Prada” in London on Sunday and told the audience that “I haven’t been able to come to many of the previews because, as you know, I have lost my eyesight.”

“So it’s hard for me to see it, but I love to hear it and, boy, it sounded good tonight,” he said.

John, 77, disclosed in September that an infection had left him “with only limited vision in one eye.” He wrote on Instagram that “I am healing, but it’s an extremely slow process and it will take some time before sight returns to the impacted eye.”

John wrote the score for “The Devil Wears Prada,” a stage musical based on the 2006 movie about a young journalist navigating the glamour and egos of a glossy fashion magazine.

The production at London’s Dominion Theatre stars Vanessa Williams as the fearsome editor Miranda Priestly, played by Meryl Streep in the film.

Sunday’s gala, a fundraiser for the Elton John AIDS Foundation, was attended by celebrities and fashion-industry figures including designer Donatella Versace and former Vogue editor Anna Wintour, the rumored inspiration for the Priestly character.

Wintour described the musical as “entertaining.”