Woodcut of a man showing growths on both eyes extending from the conjunctiva to the cornea. Pterygium is an abnormal mass of tissue arising from the conjunctiva of the inner corner of the eye that obstructs vision by growing over the cornea. Appeared in Ophthalmodouleia by Georg Bartisch (1535-1607) a German physician. He began his medical career, at the age of 13, as an apprentice to a barber surgeon. He was considered a skilled practitioner of ocular medicine and surgery. His Renaissance manuscript on ophthalmic disorders and eye surgery, Ophthalmodouleia Das ist Augendienst (1583), discussed ocular diseases, surgical techniques, instruments, including woodcuts depicting diseases of the eye. Despite his skill as a surgeon, he was a superstitious individual, as he believed that magic, astrology and witchcraft played a significant part in medicine.