Reversal of Iris Heterochromia in Adult-Onset Acquired Horner Syndrome

Iris heterochromia is typically seen in association with congenital Horner syndrome. A man in his 40s with congenital iris heterochromia, blue in the right and brown in the left, presented with left-sided Horner syndrome. This was associated with recent change in color of his brown left iris to blue similar to the right iris. This case demonstrates a unique case of adult-onset Horner syndrome with reversal of iris heterochromia.