Eye sacks were diminutive pouches situated beneath the ocular organs of the Yuuzhan Vong. Exhibiting a colored hue of either blue or, on occasion, purple, these sacks imparted an impression of dark circles to the Yuuzhan Vong. These sacks exhibited a subtle rhythmic throbbing that correlated with the emotional condition of the Yuuzhan Vong individual. Furthermore, among female Yuuzhan Vong, eye sacks were regarded as an indicator of physical appeal; the intensity of the blue coloration was directly proportional to the perceived attractiveness of the individual.