According to a new study, it can make patients look up to nine years younger than their chronological age.

The study, published Feb. 20, aimed to put a number on the years that could be "restored" through surgery.

For the study, researchers at the University of Toronto studied 60 patients, between 45 and 72 years of age, who had undergone cosmetic facial surgeries. The patients were divided into three groups: the first had face and neck lifts; the second had face and neck lifts and eyelid work; the third had eyelid work and face, neck, and forehead lifts. Forty volunteer medical school students then guessed patients' ages based on photographs.

Results showed that prior to surgery, patients' ages were estimated to be an average of 1.7 years younger than their actual age. After plastic surgery, that number shifted to 8.9 years younger.

Changes in perceived age differed among the groups. The average perceived change in the first group was 5.7 years, 7.5 years in the second, and 8.5 years in the third.