Final answer:
The most likely initial event for the development of both pinguecula and pterygia is inflammation of the conjunctiva.
Step-by-step explanation:
The most likely initial event for the development of both pinguecula and pterygia is inflammation of the conjunctiva. Pinguecula and pterygia are both characterized by the presence of nodules on the conjunctiva. Pinguecula is a yellowish nodule that forms on the white part of the eye, while pterygia are growths that extend onto the cornea. These conditions are often caused by long-term exposure to ultraviolet (UV) light and chronic irritation of the conjunctiva, such as from dust, wind, or dryness. In response to the inflammation, the conjunctiva may develop nodules as a protective mechanism.