A bunny line is a horizontal wrinkle which forms across the ridge of the nose. Commonly, people have more than one bunny line, with the lines becoming apparent when the nose moves on the face, as it often does when people smile. The “bunny” in “bunny line” is a reference to the famously wrinkled and twitchy noses of rabbits.
As people age, bunny lines tend to form naturally, as a result of years of smiling, frowning, and forming other expressions with the face. However, bunny lines can also be the result of excessive use of cosmetic procedures, especially Botox injections. When the face is essentially immobilized with Botox, sometimes the nose is the only feature which moves freely, and as a result, deep bunny lines can form.
The widespread use of cosmetic surgery and other cosmetic procedures on prominent celebrities has changed the way that many people think about aging. Bunny lines, crow's feet, and other facial wrinkles are simply the results of aging, and they are entirely natural. However, a flood of images of smooth, taut faces in the media has led some people to regard the development of wrinkles and other markers of age with distaste, leading them to opt for procedures to eliminate them.
Bunny lines are an interesting example of unintended consequences of cosmetic procedures. While most people develop bunny lines with age, these lines are typically understated in most faces, since the tissues of the face are able to move freely, without concentrating wrinkles across the bridge of the nose. However, when someone undergoes numerous cosmetic procedures to smooth the face and eliminate wrinkles, wrinkling can become concentrated in the areas of the face which can still move smoothly, and the result is often a bunny line.
Cosmetic surgeons can often spot cosmetic procedures in celebrities by looking for a pronounced bunny line, and so can you, if you are so inclined. The general immobility of the face is often a much stronger giveaway, but even if the surgery is well done enough that it could potentially fool a casual observer, a bunny line will often develop over time. In response to the formation of bunny lines, some people opt for additional procedures, creating a vicious cycle of sorts which constantly requires more procedures.