Wills Eye Hospital is talking to donors about raising money to expand its Center City campus with a new research and medical-care facility that would replace a strip of vacant houses and an empty lot.

The eye-care hospital is seeking to raise at least $30 million to build the new facility on South Ninth Street properties beside its main building at Walnut Street, chief executive officer Joseph P. Bilson said in a statement.

"This area has become a very vibrant center for health care and academic medicine," Bilson said. "We are hoping to offer even more services."

The new building would be the latest life-science facility in an area dominated by medical institutions including Thomas Jefferson University, one of the city's biggest employers.

The proposed development site consists of nine properties acquired by Wills affiliates between 1992 and 2014 for about $2.5 million, according to city records. Three were deeded for $1 each in 1994.

Five of the buildings were cited by the Department of Licenses and Inspections in March and August 2015 for safety violations including missing bricks and bulging and fractured walls.

Wills Eye spokeswoman Cathy Moss said the safety issues had been addressed or were being resolved.

She offered no further details about the expansion plans, which she said were "still evolving."

"We have a lot of wonderful things going on here, and in order to advance our scientific pursuits, we need more space," she said. The hospital offers pediatric and adult ophthalmology.

The hospital, which treats 300,000 patients a year, was ranked the country's second-best hospital for adult ophthalmology (after Miami's Bascom Palmer Eye Institute-Anne Bates Leach Eye Hospital) in U.S. News & World Report's Best Hospitals 2014-15 rankings.

Wills physicians offer advanced procedures, such as cataract surgery using computer-guided lasers and macular degeneration treatments involving telescopic lens implants.

Hospital consultant Alan Zuckerman, chairman of Veralon Partners Inc. in Philadelphia, said expansion needs at Wills were probably based on its success attracting grants to study promising treatments and its expertise in deploying established ones.

"It's very nice to have pretty, brand-new facilities, but you have to pay for them," Zuckerman said. "It's hard to imagine they'd be looking to expand to that degree if they didn't have the research profile and the patient demand to support that."