Congenital cystic eye (also known as CCE or cystic eyeball) is an extremely rare ocular malformation where the eye fails to develop correctly in utero and is replaced by benign, fluid-filled tissue.

[1] Its incidence is unknown, due to the very small number of cases reported.

[2] Embryologically, the defect is thought to occur around day 35 of gestation, when the vesicle fails to invaginate.

Dysgenesis of the vesicle later in development may result in coloboma, a separate and less severe malformation of the ocular structures.

[3] Treatment of CCE is usually by enucleation, followed by insertion of an ocular implant and prosthesis.