The most common presentation of patients with tuberculum sellae meningiomas is visual loss, and surgical resection is the main mode of treatment. Preservation of vision is not only the main objective of the surgery; loss of vision is also its main risk. Visual deterioration following surgery is usually apparent immediately post-operatively. Here we present two cases of patients who underwent resection of tuberculum sellae meningioma and whose vision following surgery was initially unchanged until the postoperative day two when dramatic visual deterioration occurred. In the first case this resulted in blindness, whereas in the second case vision recovered back to the preoperative state. The possible mechanisms of visual deterioration and modes of treatment are discussed.