The 60-year-old woman from Mississippi, U.S. had a canine tooth or "eye-tooth" extracted, shaven and sculpted then implanted into her eye as a cure for a decade of blindness.
Ms Thornton was blinded in 2000 after contracting a rare skin condition called Stevens-Johnson syndrome which caused scarring to her cornea.
The specially sculpted tooth was used as a base for a tiny prosthetic lens, her doctors said. A small hole was drilled into the tooth so the optical cylinder lens could be fitted. The lens and tooth were then inserted into Ms Thornton's cheek for two months before being implanted into her eye.
Ms Thornton's surgeon Victor Perez said the procedure, was specifically designed for patients whose bodies reject transplanted or artificial corneas.
Since regaining her sight she has been able to see seven of her grandchildren for the first time. She said: "We take our sight for granted, not realising that it can be lost at any moment. This truly is a miracle. I'm looking forward to seeing my seven youngest grandchildren for the first time."
The procedure was first pioneered in Italy but this is the first time it has been used in the United States, according to Telegraph.co.uk.