Wills Eye Hospital has moved to raze two vacant townhouses at the corner of Ninth and Locust Streets just south of its main Walnut Street building, where it has said it wants to build a new research and medical-care facility.

The eye-care hospital has filed a request with the city's Department of Licenses and Inspections to demolish the properties at 229 and 231 S. Ninth St., spokeswoman Cathy Moss said in an e-mail Wednesday.

The houses are the only standing structures on a hospital-owned strip of nine properties that are not listed on the Philadelphia Register of Historic Places.

"Wills Eye Hospital has been in discussion for several months with representatives from the city about the condition of [the] two nonhistoric structures," Moss said. "Following these discussions, we have concluded that in the interest of public safety, it is necessary to demolish these two structures."

No final decisions have been made concerning future development at the site, Moss said. The hospital has said in the past that it was trying to raise money for a new facility there.

Wills Eye would not be able to demolish or alter the remaining properties, which include three-story townhouses from the early 1800s, without demonstrating to the city's Historic Commission that their preservation would constitute a hardship that keeps them from being put to profitable use.

Paul Steinke, executive director of the Preservation Alliance for Greater Philadelphia, called on the hospital to keep the buildings intact.

"Wills Eye is one of Philadelphia's great historical medical institutions," he said. "We hope and expect that Wills Eye would abide by our city's history and incorporate those buildings into whatever development plans they have for the site."