A Biological Approach to Periorbital Aesthetics in Caucasian Females: A Review of the Literature

Abstract

 

The face plays an important role in human interactions, and the periorbital region is particularly important for recognition and attractiveness. There are several studies on the beauty of the periorbital region with a variety of methodologies, but few articles consider the attractiveness factors derived from evolutionary psychology such as symmetry, dimorphism, age and average, neoteny, and facial expression. The aim of this study was to identify periorbital attractiveness criteria in Caucasian females based on experimental studies and to interpret them in the light of studies on biological attractiveness factors. A review of literature was conducted with PubMed, the Cochrane Library Database, and EMBASE. Studies published after March 20, 2022, were analyzed, and no date limit was applied to reference papers. The search strategy was focused on 3 main concepts: attractiveness AND evaluation AND facial feature of periorbital region. A total of 780 articles were identified with this search strategy; 534 were excluded based on title and abstract and another 110 after full text assessment. Eighteen articles were finally included in the analysis. The main factors identified were an ascending intercanthal axis and eyebrow axis, a regular pretarsal plate and a well-defined upper lid crease, no scleral show, and an open eye fissure exposing the upper half of the iris. In our review we were able to identify objective anthropometric characteristics linked to biological attractiveness criteria that may be helpful in preoperative planning and assessment of the periorbital region of patients.

Level of Evidence: 3

The face plays an important role in human interactions, and the periorbital region is particularly important for face recognition, gender identification, perception of emotions such as fear, anger, and sadness, and also for assessing attractiveness.^1-4 Facial beauty has an impact on everyday life. Indeed, attractive people are perceived to have a range of positive personality traits and more positive social interactions, and are perceived as more competent.^5,6 For centuries, females have empirically increased their attractiveness with makeup and clothing. The study and theorization of facial beauty was reserved to artists to make their works more attractive. Since the nineteenth century, the development of surgical science has finally made it possible to permanently enhance facial beauty. Doctors such as Gerdy, De Fontenay, and Paul Richer were the first to discuss criteria of beauty in medicine, introducing art into science.^7-9

Today many theories of periorbital aesthetics exist but have not been integrated into a unified theory, particularly one that the clinician can apply to advantage when treating patients, making treatment of such patients more difficult. Moreover, the quality of studies on the periorbital region is heterogeneous due to subjective assessment and nonstandardized stimuli.¹⁰ If the perception of beauty is partly a personal judgment, many studies during the last 30 years in evolutionary psychology research have shown the importance of symmetry, dimorphism, age and averageness, neoteny, and facial expression in objectively assessing facial attractiveness.^11-15 Nevertheless, these factors are rarely a basis for beauty assessment in plastic surgery.¹⁶

The aim of this study was to determine criteria for the attractiveness of the periorbital region in Caucasian females based on experimental studies and interpret them in the light of studies on biological attractiveness factors.

METHODS

A review of literature was conducted with PubMed (National Institutes of Health, Bethesda, MD), Cochrane Library Database (Wiley, Hoboken, NJ) and EMBASE (Elsevier, Amsterdam, the Netherlands). Research began on March 20, 2022, and no date limit was applied to reference papers. The search equation included the following terms as keywords: (attractiveness OR beauty) AND (assessment OR analysis OR evaluation OR measurement OR rating) AND (periorbital OR eyelid OR brow OR lid OR orbital OR eye OR scleral OR pupil OR forehead OR gaze OR canthus). A manual search was undertaken in reviews but not included in this study. E.Z.B. screened titles and abstracts for potential eligibility. If the titles and abstracts did not provide enough information for inclusion or exclusion, the full text was evaluated by E.Z.B. and B.H., and any decision pertaining to including or excluding a given study was made by consensus. Data extraction was performed of all eligible articles.

Inclusion and Exclusion Criteria

We included experimental studies in which the correlation between periorbital facial features and attractiveness was evaluated in Caucasian adult female faces. We excluded articles published in any language other than English, Spanish, or French. We also excluded articles that did not include standardized photography and those including participants with significant medical history, or who had received reconstructive surgery.

RESULTS

A flow chart of the selected studies is presented in (Figure 1). A total of 788 articles were selected. Search criteria could not exclude male models, nonadults, or non-Caucasians but these were excluded after reviewing the abstracts. The abstracts of all clinical trials were evaluated by 1 of the authors. A total of 534 papers were excluded based on title and abstract. After reviewing full articles, we excluded 111 articles. Table 1 shows the different reasons for exclusion of full-text articles. There were 17 articles included in the final analysis. We have summarized the relevant articles in Supplemental Table 1 (located online at www.aestheticsurgeryjournal.com), extracting from each 1 the selected population, the number of evaluators, and the results. The main anthropometric measurements of the periorbital region are summarized in Table 2 and Figure 2. Anthropometric criteria for periorbital aesthetics are summarized in Figure 3. In contrast, an unattractive periorbital area is illustrated in Figure 4.

Palpebral Fissure

Prantl et al evaluated the periorbital region of 60 females and found that the attractive group presented a greater eye fissure height, a lower width to height ratio (WHR; 4.05 ± 0.51 vs 4.76 ± 0.64), a greater visible height of iris, and a lower scleral show compared to the unattractive group.¹⁷

McDonnell analyzed 22 eyes and also found a correlation between reduced attractiveness and the presence of scleral show.¹⁸ Rhee et al found more attractive composite faces with the following eye fissure values: eye fissure height (EFH) = 10.72 mm, eye fissure width (EFW) = 28.94 mm.¹⁹ Concerning the intercanthal axis, a positive value enhanced attractiveness according to several studies.^17,20,21 An accentuated medial canthal tilt may also improve attractiveness through the illusion of an accentuated intercanthal axis.²²

Upper Eyelid

By comparing attractive and less attractive females, McDonnell et al found respectively a pretarsal space (PS) 2.97 mm ± 0.90 vs 4.97 mm ± 2.17 and a ratio of upper lid fold (ULF) to PS of 3.27 ± 1.19 vs 2.60 ± 1.02.¹⁸ Vaca et al found a similar PS at midpupillary, approximately 2.3 mm ± 0.9, and the same ULF/PS 2.8 ± 2.2 ratio, but this ratio was put into perspective by its high amplitude in the attractive eyes (between 1.8 to 8.8).²³ This study additionally reported that in the attractive group maximal height of the PS was more lateral than in the unattractive group.

Eyebrow

Prantl et al found a greater inclination of the eyebrow and a more lateral origin of the medial brow in the attractive group than in the less attractive group.¹⁷ In contrast, Vaca et al reported that the medial brow origin was more medial in the attractive group, but agreed on the importance of brow orientation; they observed a consistent pattern in which the lash line peak, eyelid crease peak, and brow peak were progressively more laterally located in attractive eyes, and that attractive eye curvature peaks were in close agreement with the golden spiral in attractive faces.²³ Hamamoto et al analyzed the different eyebrow patterns given by Westmore, Lana, and Anastasia without finding superiority of one pattern over another.²⁴ Gülbitti et al found that the “low” eyebrow position was preferred, and this fact was supported by Feser et al, who further highlighted that people under 50 years old preferred an eyebrow in a low position with a peak at the lateral third. In contrast, evaluators over 50 years old preferred eyebrows with a medialized peak.^25,26

DISCUSSION

The search for aesthetic measurements with the aim of reproducing beauty has existed since antiquity and continues to this day. To date there is no consensus on the ideal proportions of the periorbital region and determining objective anthropometric criteria remains a difficult task.

Upon review of the data, the diversity of the population and the nonstandardized measurements in the studies make comparison difficult. Moreover, it is very important to note that there is a great variability in anthropometric measurements in the periorbital region of attractive people, such as the position of the upper lid crease and height of the eyebrow.²³ Despite these difficulties, we think that we can provide reliable trends regarding the factors that make the periorbital region attractive; these are summarized in Figure 3.

Beyond the simple application of measurements in surgical practice, we think it is essential to understand why certain measurements seem more pleasing than others. In our opinion, it is also illusory to look for a ratio that can, on its own, determine beauty. To provide a basis for reflection on beauty, we have chosen a biological approach, that is, an approach to aesthetics based on the conclusions of evolutionary psychology studies. After a study of this literature, we selected the following attractiveness criteria, which can be summarized by the acronym NAIADES (neoteny, age, integument, averageness, dimorphism, expression, and symmetry; Figure 5). The correspondence between the anthropometric data retrieved and these factors is detailed below.

Age is a major component of female attractiveness.^27,28 In our results, age had a major impact on perceived attractiveness, and anthropometric measurements must be put in the context of the aging process.^{17,18,25,29,30} With age, ptosis of the upper eyelid covers more of the upper part of the iris, and ptosis of the lower eyelid uncovers the sclera under the iris. The palpebral fissure narrows, decreases in height, its width becomes rounder, and the intercanthal axis falls.^31,32 All these parameters are correlated to a decrease in attractiveness (Figure 5). Also, the pretarsal plate increases with age due to ptosis of the upper eyelid.^17,31 Age-related excess skin increases the ULF, obscures the upper lid crease, can close the orbital fissure, and alters the definition of the periorbital region. With age, the medial margin of the eyebrow rises while the lateral margin falls, modifying the axis of the eyebrow and medializing its peak.³³

Gülbitti et al analyzed the position of the eyebrow relative to the eyelid-cheek junction.²⁵ According to the oval balance principle, a low eyebrow combined with a high eyelid-cheek junction was evaluated as more attractive, with a narrow oval corresponding to a younger look. The second most attractive configuration is a high eyebrow and low eyelid-cheek junction, corresponding to a balanced look. For Lambros et al, the lid-cheek junction does not come down with age.³⁴ For Haddock et al the fall of the lid-check junction is improbable due to the ligamentous nature of the fold.³⁵ The emphasis of the palpebrojugal fold or tear trough deformity may be caused by various factors: periorbital skin atrophy, herniation of the periorbital fat due to weakness of the orbital septum and the orbicularis retaining ligament (ORL), bone atrophy, or atrophy and descent of the malar fat pad.^36,37 The skeletal changes associated with the loss of septal rigidity and change in the distribution of periorbital fat leads to lower eyelid “bags” correlated with a decrease in attractiveness.³⁰ Bone aging in the periorbital region has been studied by Bartlett et al and Richard et al in scanographic study of a Caucasian, confirming Lambros’s algorithm corresponding to an anterior displacement of the skeleton superior to the orbit and posterior displacement of the skeleton inferior to the orbit.^38-40 In upper orbital fat there is a noticeable increase in the volume grade of the nasal fat pad, whereas the volume of the central pad decreases over the years, increasing the pretarsal plate and creating the “A-frame deformity.”⁴¹ This finding is supported by Vaca et al, who reported that in the attractive group the maximal height of the PS was more lateral than in the unattractive group and can be explained by alterations in the periorbital fat during aging.²³

Dimorphism refers to the differences between adult male and female; it is a major factor of female attractiveness, and from an evolutionary perspective it indicates a hormonal balance, health, and sexual maturity.^5,12,42,43 Averageness refers to the concept that average or typical facial features tend to be perceived as more attractive. This phenomenon is thought to be influenced by evolutionary factors and is linked to the idea that average features might convey genetic diversity and health.^11,44 In contrast to males, females have a relatively smaller palpebral fissure dimension; however, its prominence in relation to facial size is more accentuated.⁴⁵ Eye fissure shape tends to be rounder in females, with a reduced WHR, leading to increased visibility of the upper portion of the iris.⁴⁶ Moreover, the intercanthal axis is observed to have a more upward orientation in females.^32,47,48 All these morphological characteristics regarding dimorphism are found in the most attractive eyes. Rhee et al compared measurements of attractive and average composite faces and found that eye fissure height and width were similar in the average and the attractive face, respectively 10.72 mm, 28.94 mm, and 12 mm, 27.45 mm.³⁷ However, the intercanthal angle varied significantly and was higher in attractive females, 4.12° vs 7.13°. These measurements are similar to those found by Kunjur et al and Price et al in Caucasian females.^47,48 These findings are correlated with the idea that attractive faces often have average values. However, highly dimorphic features such as the intercanthal angle increase attractiveness when they exceed normal ranges.⁴⁹ For eyebrows, the differences are significant. The brow is thicker in males, and its angulation is neutral.⁵⁰ Some of these variations in position can be attributed to the bone structure of the periorbital region in males, compared to females. It is characterized by a more prominent glabella, a compact supraorbital hump, and a less smooth orbital rim. In addition, the fat pad of the eyebrows tends to be more voluminous.⁵¹ As a result, the eyebrows are lower, and the eyelid fold is smaller and covers part of the pretarsal plate, widening the eyelid fissure (Figure 6).^31,45,48 For Price et al and Van den Bosch et al, the average values of the PS in young Caucasian females respectively were 3.3 ± 1.6 and 3 mm, whereas they were 2.0 ± 1.2 and 2.1 ± 2.2 mm in males.⁴⁵

Symmetry has always been described as a major factor of attractiveness. From an evolutionary perspective, symmetry is an indicator of genetic quality, immunocompetence, good health, and an individual's ability to avoid pathogens.^11,52,53 Springer et al modified the symmetry of the inner and outer canthus by computer, and found that an upward asymmetry of the outer canthus has less impact on attractiveness than a downward lateral canthus, or than the asymmetry of the inner canthus.⁵⁴ This study highlights the fact that increasing dimorphism is more important for attractiveness than perfect symmetry of the external canthus. The correlation between reduced attractiveness and asymmetries in the internal canthus can be explained by the unconscious signaling of a developmental anomaly, the presence of an “unhealthy” genotype. We did not find a study of evaluation of the link between the perception of asymmetry and the attractiveness of other components of the periorbital region. However, several studies have highlighted the fact that each facial zone has a threshold at which symmetry becomes perceptible. For Wang et al the periorbital region has the lowest threshold and sets it at 1 to 2 mm for the eyelid and 3.5 mm for the eyebrows, which can be considered values not to be exceeded to correct an asymmetry.⁵⁵

Color and texture of integuments (the skin and annexes) to which we can add the visible part of the globe are important elements of facial attractiveness. They indicate health, youth, and hormonal balance. Provine et al found that the eyes were perceived as older, less healthy, and less attractive with a reddened or yellowed sclera but without change when the sclera was bleached compared to the control.²⁹ These results are confirmed by those of Gründl et al, who found a correlation between attractiveness and age, pupil diameter and scleral brightness, but no correlation between iris color and attractiveness.⁵⁶ Peshek et al found a correlation between the presence of the limbal ring and attractiveness as a feature that increases contrast with the sclera.⁵⁷ None of our studies describe specifically evaluating skin texture or periocular color (dark circles under eye) but they are obviously involved in judging age and attractiveness and represent an important part of patients’ requests.^58,59

Facial expressions have an important impact on attractiveness. Facial expressions conveying emotions such as anger, sadness, tiredness, and disgust decrease attractiveness, while expressions such as joy increase it.⁶⁰ Due to aging or excess of surgical procedures, some morphological features can convey the image of a sad, tired, or surprised look that is not correlated with an emotional state. Forte et al found a correlation between lower lid fat herniation, upper eyelid ptosis, and perception of tiredness, age, and attractiveness.³⁰ Gülbitti et al found that a higher lid-cheek was linked to attractiveness and the perception of happiness, compared to a low lid-cheek position that is assimilated to sadness and tiredness.²⁵ This can be explained by the contraction of the orbicularis muscle during the real smile (Duchenne smile). Knoll et al studied the relationship between periorbital aesthetics related to surgical blepharoplasty and perceived emotion.⁶¹ Tiredness was linked to upper eyelid ptosis (increased PS) and a fall of the lateral brow. An elevated lateral eyebrow was associated with an expression of surprise, while a low medial eyebrow was assimilated with anger and disgust.

In biology, neoteny is defined as the preservation of infantile morphological characteristics when the individual has arrived at sexual maturity. In adult females, some facial characteristics corresponding to this baby schema are correlated with facial attractiveness, such as the relatively large size of the eyes (Figure 6).^13,62,63

Results related to the wider dimensions of the palpebral fissure and the exposure of the upper part of the iris in attractive eyes are consistent with this theory. Chen et al hypothesized that the upper lid crease would influence the perception of eye size through the Delbeouf optical illusion, a visual perception phenomenon in which an object appears larger when surrounded by a smaller concentric circle.⁶⁴ We can see that the most attractive periorbital regions are those with a succession of tight circles: a large pupil, a limbal ring, a thin pretarsal plate and a small “orbital oval.” The precise definition of these elements is a factor to be taken into account.⁶⁵ Naran et al increased the intercanthal distance by 110%, resulting in friendlier and more attractive faces.⁶⁶ These results may be related to the baby schema due to the relative hypertelorism of newborns.⁶⁷

The anthropometric results found can help surgical planning. We suggest procedures based on anthropometric changes. Blepharoplasty reduces ULF and increases PS. Ptosis surgery opens the eye fissure and reduces the PS, and combined with blepharoplasty increases the PS.⁶⁸ Canthopexy increases the intercanthal axis and is a treatment for scleral show.⁶⁹ The volumes of the fat compartments can be treated by removal or volumized with fillers or fat grafting or even transposition.⁷⁰ Fat grafting is probably the best method and for A-frame or C-frame deformity; it can increase ULF and reduce PS.⁷¹ The position of the eyebrow can be changed with a brow lift or, for minimal changes, with Botox.⁷² A combination of midface and fat grafting may be considered on patients with negative lower eyelid vectors or a pronounced lid-cheek junction. As part of facial feminization, a modeling of the orbital rims and eyebrow bumps may be considered. The tegument aspect can be improved by cosmetic procedures, physical and chemical agents such as peeling, laser, plasma inducing neocolagenesis, or blepharoplasty in the case of associated skin excess. Wrinkles can be reduced with Botox, and eyebrow appearance can be improved with hair grafting. Simple cosmetic procedures can help the surgeon improve the aesthetic results, such as tattooing to increase the thickness, color, and position of the eyebrows.

Concerning methodology, we chose experimental studies for the most objective evaluations of attractiveness. Studies concerning models or celebrities without objective evaluation were rejected because they may be more subject to fashion effects and photography modification or selected for other criteria such as distinctiveness to facilitate recognition.⁴² We have also excluded studies related to the analysis of works of art because these are not necessarily applicable to plastic surgery.⁷³ This selection of studies enabled us to improve the reliability of our results. These were compared with findings of other studies that were linked to biological attractiveness criteria, unifying the existing literature and bringing external validity to the results. Our article has intentionally focused on the Caucasian physiognomy for several reasons: there are far fewer prospective studies on Asians and even fewer on Africans. Moreover, Asian anatomical variations require a different approach to the analysis of the periorbital region: presence of an epicanthus, pretarsal space less present, and an accentuated intercanthal axis. Future studies should focus on the specific attractiveness of other ethnicities, such as Asians or Africans. Some of our studies did not exclude ethnic groups but included countries in which Caucasian females were in majority.^17,74

This study had some limitations. Most of the studies focus on anthropometric data, and unfortunately terms, measurements, and ratios are not standardized. This limits comparison between the various available measurements. We decided not to overload this review with numerical data for previously given reasons and because anthropometric measurements are rarely part of practice. In addition, future studies should focus on anatomic structures and their correlation to external landmarks. These can be useful to the surgeon when planning surgery. It is important to note that some studies have shown differences in the perception of attractiveness criteria of the periorbital region by the age of the evaluators. Indeed, Feser et al found that people over 50 years old prefer an eyebrow with a medialized peak.²⁶ Additionally Gründl et al found that this population tends to prefer a neutral intercanthal axis.²¹ In our opinion these results can be explained by a change in fashion or by an eyebrow model closer to their age group, which are difficult to interpret. This effect should be studied more deeply because of the wide age range of patients seeking consultation.

CONCLUSIONS

Determining attractiveness criteria for the periorbital region is necessary to guide the surgeon in operative planning and improving patient satisfaction. Despite the growing number of studies with an evidence-based approach, we are not in a position to give a definitive answer. Nevertheless, after a review of the literature, we have collected enough data and concordance between studies to determine some elements that make the female Caucasian periorbital region attractive. The ideal brow starts at the around the medial canthus and ascends to peak at the middle third–distal third junction, and is harmonious with the lid crease and lash line. The proportion of upper lid spaces (ULF/PS) is one of the determining factors of attractiveness rather than absolute values, averaging 1.8 medially to 3 laterally in attractive eyes. The ideal height of the pretarsal space is between 2 and 3 mm. The palpebral fissure height in relation to iris show is critical to the perception of attractive eyes. The ideal intercanthal axis is oriented upward (positive canthal tilt).

We have also provided a basis for thinking about attractiveness by interpreting the data with anatomical studies and attractiveness criteria from the evolutionary psychology literature that we believe apply to the periorbital region. In other words, a periorbital region is attractive if it has youthful features, resembles a female pattern, is symmetrical, has certain neotenic features, has integuments that indicate good health and youthfulness, and expresses positive emotions. It can be summarized with the anagram NAIADES (neoteny, averageness, integument, age, dimorphism, expression, and symmetry).

Supplemental Material

This article contains supplemental material located online at www.aestheticsurgeryjournal.com.

Disclosures

The authors declared no potential conflicts of interest with respect to the research, authorship, and publication of this article.

Funding

The authors received no financial support for the research, authorship, and publication of this article.

REFERENCES

Author notes