Coloboma of superior eyelid is a rare developmental defect that occurs during embryogenesis, characterized by a partial or complete absence of the upper eyelid, most often presenting as a triangular defect on the medial third of the lid. This condition can be isolated or occur alongside other ocular, orbital, or facial anomalies. It is typically recognized in infancy or early childhood, although the severity and precise features can vary widely. Because detailed prevalence data are not available, current understanding of this condition continues to evolve with ongoing research.

Individuals with coloboma of the superior eyelid usually present with an abnormal notch or absence in a portion of the upper eyelid that may range from a small defect to a complete loss of tissue. The defect is typically triangular in shape, with its base at the eyelid margin, and it most often affects only one eye. In some cases, additional ocular or facial anomalies may be present, although not all individuals experience these associated features. Not all individuals experience all features, and severity varies considerably.

The precise genetic basis of coloboma of the superior eyelid is currently under investigation, and no specific genes have been identified to date. Likewise, a clear inheritance pattern has not been established for this condition. Families with questions about recurrence or genetic risks are encouraged to consult with a genetic counselor to explore available options and receive personalized guidance.