Eye Shape Illusions Induced by Eyebrow Positions

Abstract

We investigated whether the position of the eyebrows influences the perceived shape of the eyes by employing psychophysical measurements. Experiment 1 used arched and straight eyebrows at five different inclinations as stimuli and measured the perceived inclination of the eyes. The results demonstrated that the eyes are perceived to be somewhat inclined in the same direction as the eyebrows. Experiment 2 measured the perceived eye size by manipulating the distance between the eyes and the eyebrows and the curvature of the eyebrows across three levels. The results showed that the lower eyebrows (ie closer to eyes) made the eyes appear larger and the higher eyebrows made the eyes appear smaller, while eyebrow curvature had no effect on perceived eye size. Experiment 3 examined the role of the eye-eyebrow distance in the eye inclination illusion shown in experiment 1. The eye inclination illusion was unaffected by the eye-eyebrow distance, suggesting that the eye inclination illusion and the eye size illusion may involve different kinds of assimilation. These illusions are discussed in terms of face perception and possible practical applications.

Effects of Lip Color on Perceived Lightness of Human Facial Skin

“…One tendency is assimilative: Geometric illusions in body parts tend to induce illusions of assimilation instead of contrast. And Morikawa also observed that in the human face and body, the visual property of a smaller region can spread to larger adjacent areas, a phenomenon that he called “visual echo illusion.” These tendencies of biological illusion have been confirmed by some other studies (Matsushita et al., 2015; Morikawa, 2017). Indeed, the present study’s results seem to accord with the theory of biological illusion.…”

“…Face perception and lightness illusion (e.g., lightness perception is affected by the lightness of adjacent areas) have been investigated separately by numerous studies (Adelson, 2000; Tanaka & Farah, 1993) and are already established as different research fields with very little relationship. In addition, in recent years, perceptual effects of cosmetics have begun to draw attention as a promising new field of perceptual study (Matsushita, Morikawa, Mitsuzane, & Yamanami, 2015; Morikawa, Matsushita, Tomita, & Yamanami, 2015). However, very few studies, if any, have tackled the intersection of these three fields.…”

“…Although several studies have examined shape or size illusions in faces (Lee & Freire, 1999; Matsushita, Morikawa, & Yamanami, 2015; Morikawa et al., 2015), illusion of facial color or lightness remains largely unexplored. Makeup artists and advertisements for cosmetics often claim that lip color can influence facial skin’s apparent lightness (e.g., http://verilymag.com/2015/02/best-lipstick-skin-tone).…”

Chen’s Double Eyelid Fold Ratio

“… 24 The shortened distance between the eyebrow and eye is reported to increase the illusion of a larger eye. 25 Hence, the visually perceived dimension and aesthetics of the eye are further influenced by the relative proportions of the eyebrow–eye anatomical unit. 19 In this study, the vertical ratio of the actual eye fissure in the eyebrow–eye unit was significantly increased by 34.4%.…”

“The Evolution of Eyebrow Morphology: The Westmore Model Revisited”

“…The eyebrow plays a significant role in communication. 1 It conveys a wide range of expressions, such as sadness, anger, satisfaction, and joy. 2 Since the beginning of human civilization, it has been recognized as a key element in facial aesthetics.…”