In 16 years as a professional boxer and mixed martial arts fighter, Marcus Davis has received stitches above his eyes 77 times. The cuts have affected him: doctors have stopped fights, and his battered face, he says, has influenced judges’ decisions.

So last summer, Davis, 35, contacted a plastic surgeon in Las Vegas. He wanted to make his skin less prone to cutting.

The surgeon, Dr. Frank Stile, burred down the bones around Davis’s eye sockets. He also removed scar tissue around his eyes and replaced it with collagen made from the skin of cadavers.

Now, at least in theory, when Davis takes a blow to the face, he will be less likely to bleed.

Medical researchers have not analyzed the procedure, and until they do, the American Society of Plastic Surgeons will not comment on its efficacy. But Davis and several others swear by it.