Doctors in Massachusetts helped save a 27-year-old landscaper's vision and possibly his life after a three-inch nail suddenly speared him in the right eye while he was weed whacking.

Doctors described the lucky Boston man's case in Thursday's New England Journal of Medicine.

About two years ago, surgeons from Massachusetts General Hospital successfully removed the nail and gave him a tetanus shot and antibiotics.

Remarkably, they said, his vision returned to normal eight weeks later.

Doctors said if the nail had pierced his eye even one millimetre away, the consequences could have been dire.

They warn that wearing eye protection is vital, even while gardening.