PHOTOS: Smoking Makes You Look Older

It's official: Smoking makes you look old.

A new study in twins, published in the journal Plastic and Reconstructive Surgery, shows just how much smoking prematurely ages your face. And the results are stark.

Researchers from University Hospital Case Medical and Case School of Medicine found that smokers tended to have more upper eyelid sagging, under-eye bags and wrinkles, among other indicators of aging.

For the study, 79 pairs of twins with an average age of 48 who attended the annual Twin Days Festival in Twinsburg, Ohio, were professionally photographed. For each of these pairs of twins, one of the twins smoked, while the other did not, or one of the twins smoked for at least five years longer than the other twin.

Then, plastic surgeons looked at these photographs of the twins and pointed out "specific components of facial aging." Among twins where one twin was a smoker and one twin had never smoked, the smoking twin had more lines between the nose and the mouth (also known as nasolabial folds), lip wrinkles and sagging jowls, in addition to the under-eye bags and sagging eyelids.

And "among twins with greater than five years' difference in smoking duration, twins who had smoked longer had worse scores for lower lid bags, malar bags, and lower lip vermillion wrinkles," the researchers wrote in the study.

Interestingly, most signs of aging linked with the smoking were seen in the middle and bottom part of the face.

See the facial differences between the non-smoking/less-smoking twins and the smoking twins by sliding your cursor from right to left across the image:

These twins both smoke, but sliding your cursor from right to left reveals the twin who smoked 17 years more.

The twin on the left is the nonsmoker, while the twin on the right smokes.

The twin on the left is the nonsmoker, while the twin on the right is a 29-year smoker.

These twins both smoke, but sliding your cursor from right to left reveals the twin who smoked 14 years more.

Photos courtesy of the American Society of Plastic Surgeons.