Steve Mann, who designed a vision device similar to the enhanced reality glasses recently announced by Google, said he and his family were vacationing in Paris and stopped by the Champs Elysees McDonald's on July 1.
In his blog, Mann wrote that he showed McDonald's staff a note from his physician and accompanying documents about the glasses, but that three staff members knocked the device off his head and grabbed it.
"McDonald's was the only establishment that seemed to have any problem with my eyeglass during our entire 2 week trip," Mann wrote, describing the three employees as Perpetrators 1, 2 and 3. He said when the first staffer grabbed the glasses, he recorded images of the confrontation. But the lens was damaged, said Mann, a professor of computer engineering at the University of Toronto.
On its Facebook page, McDonald's France wrote that as part of its inquiry officials have spoken with Mann and the employees.
The staff said they were concerned about privacy violations when they approached Mann, according to the statement. McDonald's did not say if the staff members admitted knocking the glasses off Mann's head.
"According to the employees, the exchanges with Mr. Mann were respectful and polite," the company said. "Regarding the emotion this affair has generated, McDonald's asks that no one jump to conclusions before all the facts are known."
Mann has said he hopes the glasses will ultimately help the visually impaired. He did not immediately respond to requests for comment Thursday.