Pilocytic astrocytoma is a central nervous system neoplasia that arises during pediatric age. Only few cases have been documented in patients older than 50 years old. It is a low-grade lesion that can rarely undergo malignant changes presenting the histologic features of a high-grade glioma. We report a case of a pilocytic astrocytoma arising in the eyeball of a 53-year-old man affected by glaucoma that underwent malignant evolution.