What is the most common cause of pinguecula/pterygia?

• A. UV light exposure
• B. Smoking
• C. Bacterial infection
• D. Trauma

Answer: (A)

Chronic exposure to ultraviolet radiation from the sun is the primary factor driving the development of pinguecula and pterygium. Repeated UV damage to the bulbar conjunctiva and limbal region triggers degenerative changes in the tissue and stimulates fibrovascular growth toward the cornea. This sun-driven process leads to a pinguecula as a yellowish, elevated spot on the bulbar conjunctiva near the limbus and can progress to a pterygium that encroaches onto the cornea. Outdoor exposure, especially in sunny climates and with wind or dust irritation, markedly increases risk. Other options like smoking, bacterial infection, or trauma are not the typical initiating causes of these lesions, though they may affect other ocular surface conditions or progression.