Long eyelashes
Page most recently updated 7 September 2026
This page focuses on long eyelashes as a morphologic feature of conditions that may also be associated with psychiatric manifestations, such as psychosis, mania, autism spectrum disorder, ADHD, OCD, and self-injurious behaviours. The page begins with a clinical definition of long eyelashes based on the standardized Elements of Morphology terminology, together with visual examples from the same source. This is followed by a list of conditions in which long eyelashes have been described in association with psychiatric manifestations.
Of note, to optimize clinical utility, the list does not include conditions associated with intellectual disability in the absence of other psychiatric features.
Each condition listed below is linked to a dedicated page within this resource. These pages describe the psychiatric manifestations associated with each condition, as well as other morphologic and broader clinical features, allowing the differential diagnosis to be considered from multiple perspectives.
Long eyelashes
This boy has long eyelashes. In addition, the eyelashes are unusually angled, although this feature is not required for the definition of long eyelashes.
Image credit: National Human Genome Research Institute (NHGRI), Elements of Morphology.
Definition
Subjective: Increased length of the eyelashes.
Objective: Mid upper eyelash length > 10 mm.
Note: Measurement should be done on the longest lashes, which are usually at the center of the lid.
Synonyms: Ciliary trichomegaly.
Conditions with potential psychiatric associations
Selected references and further reading — Morphologic lens
Allanson JE, Biesecker LG, Carey JC, Hennekam RCM. Elements of morphology: introduction. Am J Med Genet A. 2009;149A(1):2-5.
Hennekam RCM, Biesecker LG, Allanson JE, Hall JG, Opitz JM, Temple IK, Carey JC; Elements of Morphology Consortium. Elements of morphology: general terms for congenital anomalies. Am J Med Genet A. 2013;161A(11):2726-2733.
Jones KL, Jones MC, del Campo M. Smith's recognizable patterns of human malformation. 8th ed. Philadelphia: Elsevier; 2021.
Reardon W. The bedside dysmorphologist: a guide to identifying and assessing congenital malformations. 2nd ed. Oxford: Oxford University Press; 2016.