“Round or circle-eyed” giants populated Greek-Roman mythology. Homer described them as mortal herdsmen sons of Poseidon.
In Biology it is established that “veratrum californicum, album”, or other related herbs contain teratogens (cyclopamine and jervine) that cause cyclopia in grazing animals. Among humans, trisomy 13 and other causes may manifest as partial or near total fusion of orbits and its contents. Usually such congenital malformations are associated with anomalies of the frontal cerebral lobe that fails to divide and control the development of the nose (proboscis). Please search for companion illustrations (requires registration/subscription).