Research has revealed compelling evidence regarding the perception of individuals with sleep debt. Others often see them as less attractive, less healthy, and sadder [2,3,4]. Also, acute sleep deprivation is linked to paler skin and increased wrinkles [4]. As such, a previous study showed that people with obstructive sleep apnea, a condition that disrupts sleep quality and leads to premature awakening, are perceived as older unless they undergo treatment [7].

Expanding on the concept that poor sleep patterns may be associated with facial aging, our study demonstrates that a man was perceived as 2.9 years older in a photo taken after 42.6 h of continuous wakefulness compared to his actual age when the photo was taken. These findings raise concerns about potential biases faced by individuals experiencing chronic sleep deprivation, such as shift workers or caregivers of young children, based on how they are perceived in terms of age. Such biased judgments can harm their self-esteem, relationships with others, and professional opportunities. Conversely, these findings could indirectly suggest that prioritizing better sleep habits may result in a younger facial appearance, a result that could assist health practitioners and public health professionals in motivating people to prioritize sleep.

Another noteworthy discovery from our study is the correlation between observer sleepiness and their perception of the photographed individual’s age. As per the 10-point scale employed in this study to assess the subjective sleepiness of observers, age estimations could vary by up to 2.6 years due to variations in subjective sleepiness among observers. These findings suggest that sleepiness can change how the brain processes visual information, including facial features. This is supported by previous research indicating that images of natural scenes are rated as less pleasant after sleep loss compared to after a full night’s sleep [8].

While this study offers valuable insights, it is essential to consider several limitations when interpreting the findings. Firstly, photographs were gathered from the same individual across various sleep debt states during the survey to minimize potential variations in the observed effects, as different faces might have varying levels of salience. Consequently, it remains uncertain whether similar effects of sleep loss on facial age appearance occur in women, individuals of diverse ethnic backgrounds, and other age groups. Another limitation lies in the participant selection process, where respondents were self-selected, potentially resulting in a sample that may not fully represent diversity or offer a truly representative cross section. Nevertheless, despite these limitations, the current study underscores the significance of sleep’s role in the social perception of individuals.