Hilary Duff at DSquared eyewear launch.

Hilary Duff took a break from "Gossip Girl" to attend last night's DSquared eyewear launch event. Photo: Donald Bowers, Getty Images

DSquared now makes eyewear!

Designers Dan and Dean Caten already dress celebrities -- including outfitting Britney Spears for many a tour date -- in their body-conscious looks and now the design duo is making the most necessary celebrity accessory: sunglasses.

At last night's launch event in a far west Chelsea warehouse in NYC, the designers were all smiles in trim tuxedo blazers.

"It's more straightforward and not too blingy, and it's also a bit masculine-y, so it can be unisex," Dean told StyleList of the new line.

While the design duo weren't inspired by any particular celebrity, they still had the famed hills in mind. "It's old Hollywood meets new Hollywood!" Dan added.

And the celebrities turned out in droves. Rachel Zoe confessed that Fashion Week was "fashionably exhausting" but still made it out for the red carpet.

Of the runway shows she's seen, the celebrity stylist/reality TV star loved Marc Jacobs, Derek Lam and on designers Kate and Laura Mulleavy, Zoe adds, "Rodarte almost made me cry it was so amazing."

Wearing head-to-toe DSquared, but accessorizing with a Goyard clutch, Hilary Duff sang the duo's praises. "DSquared is one of my favorite lines. I've always had a huge respect for designers for their vision and creativity. Maybe I'll get to be there someday. My line [with DKNY] is more for everyday, but it was still a little nerve-wracking."

Inside the two-story warehouse space there were models aplenty, including Tyson Beckford, making the rounds in the line's new shades.

But the roof was where it was at. With a view that included the Empire State Building, guests whiled the night away drinking champers and dancing to the live DJ. Only two more days to go for New York Fashion Week!

We're glad to see the label being so practical -- after all, sunglasses are one accessory that's good for you!