In the land of facial expressions, there are many, many facial actions that are easy to confuse and difficult to tell apart. Among the contenders for most-difficult-to-distinguish-facial-actions are two upper lip elevators known as upper lip raiser and nasolabial furrow deepener. (These terms are defined by the Facial Action Coding System – FACS.)
Many facial movements look similar but differ in core ways. When we read faces, we rely on subtle differences to interpret expressions and their meaning. Because your audience will be likening your character’s facial expressions to what they already know and have experienced, you want your character to be readable – to be relatable.
The depth and amount of lid skin in people with upper lid creases is highly variable! This is one of the many reasons eyeliner users can’t approach lining the same way. Got secrets hidden in there.
We are generally familiar with frontalis’s work as an eyebrow elevator; however, it is often neglected knowledge that frontalis also works as a hairline depressor. Though this idea may seem counterintuitive, once you are familiar with some muscle basics, things will start to make sense.
Chimpanzees and humans have many things in common when it comes to facial expressions and facial structure; however, they also have many significant differences! Below is a series of imagery focusing on an action affected by the prominent brow ridge seen in chimpanzees: cheek raiser – an orbicularis oculi (orbital portion) action. Observe the key differences and similarities.
In FACS, upper lid raiser, or AU5, is the action that raises and retracts the upper eyelid; this movement causes the eyes to appear wider and reveal more sclera (the white part of eye). The appearance changes we see in upper lid raiser are the result of an increase in contraction of levator palpebrae superioris, an extraocular muscle that works to keep the upper eyelid elevated.
