Background: Epithelial iris cysts are derived due to genetic factors or caused by ocular trauma. Case Report: We report the case of a five-year-old boy with blurred vision after a rubber bullet toy hit his left eye. There was a wide iris cyst of more than 180º in extent, attached to the corneal endothelium on the nasal side, with a still clear cornea. His vision in affected eye reduced to hand movement with intraocular pressure of 40 mmHg. The whole cornea was edematous and the iris cyst had grown significantly in terms of size. We performed a successful iris cyst removal followed by Ahmed drainage implant that resulted in moderate visual improvement. Conclusion: Iris cyst can develop secondary to neglected ocular trauma.