Since opening his own retail eyeglass business in 2002, Cliff Balter has known a number of indignities. Perhaps the most obnoxious affront rolled up outside his Philadelphia shop on back-to-back Saturdays in November 2012.

It was a mobile showroom for Warby Parker, an online company launched by four students from the Wharton School at the University of Pennsylvania. Their goal was affordable convenience: to bring shoppers, without leaving their homes, stylish eyewear priced from $95.

"I was a little [ticked]," acknowledged Balter, 40, "but I thought it was a great idea."

And a great motivator, he said: "It made us go back to work harder."

Balter had been working on re-envisioning what was then known as InnerVision EyeWear, where customers routinely spent $1,500 on a pair of glasses. He had thought about adding an in-house lab to reach lower-priced customers and also an online piece.

Still, that rethinking had been more like "a hobby," Balter said.

He decided on an "unusual, fun, diverse" look to distinguish Philly EyeWorks from what Balter described as Warby Parker's "contemporary, news-anchor glasses."

The Philly EyeWorks brand and website launched in August 2014, sharing its premises with InnerVision. Its frames, made in China, arrive clear with a glossy finish, and then are hand-colored and sandblasted. There are close to 400 color combinations for glasses that start at $150.

The styles have Philly-centric names, such as Yo Adrian, No Libs, Liberty Bell and Brotherly Love.

Balter would not disclose financials, saying only that sales at his company of eight full-time employees, including his wife, Emily, are up 300 percent over a year ago.

Now another challenge lurks. Following a retail trend, Warby Parker, that company of online origins, now has 30 brick-and-mortar shops, including a small showroom in Philly, with plans to add another around the corner from Philly EyeWorks.

Balter is not sitting still. He guarantees he has something up his sleeve to compete.