This article received lots of press. Researchers took photographs of subjects after 8 hours of normal sleep and after 31 hours of sleep deprivation following only 5 hours of sleep the night before. The researchers then asked volunteers to list facial cues they associate with looking fatigued. The final list consisted of hanging eyelids, red eyes, swollen eyes, glazed eyes, dark circles under the eyes, pale skin, wrinkles around the eyes, rash / eczema, and droopy mouth corners. Finally, the researchers had participants rate the photographs for the fatigue cues.
The results showed that the fatigue cues were significantly found in the photographs of sleep deprived subjects - no big surprise. With the exception of glazed eyes, all of the cues that correlated with looking fatigued were also affected by sleep deprivation.
This research is interesting in that these cues for fatigue may help others determine if someone is too fatigued to be safe at work or while driving.