A schematic drawing of the upper eyelid and a possible mechanism underlying the presence of a DUES-like appearance.

a. A schematic drawing of the upper eyelid associated with natural open eyes. b. A schematic drawing of the upper eyelid associated with wide-open eyes. A DUES-like appearance occurs when LA draws OS and fat toward the back of the eyeball. LPS: levator palpebrae superioris muscle, WL: Whitnall ligament, OF: orbital fat, OS: orbital septum, AL: anterior layer of LA, PL: posterior layer of LA, FA: fibroadipose layer, OCM: orbicularis oculi muscle, ROOF: retro-orbicularis oculi fat; SR: superior rectus muscle. The black arrow indicates the DUES-like appearance. The red dotted arrows show the effects of the LPS and LA.