Pterygium is a frequent ocular disease whose etiopathology is not completely known. Several factors are considered involved in pterygium formation and progression, among which light exposure, age, dry eyes condition, bacterial infections or genetic predisposition. The purpose of our study was to perform a partial evaluation of the social history of 118 patients with pterygium. All of them presented lesions of various sizes, unilateral or bilateral, and underwent surgical removal. We have analysed potential correlations between the degree of progression (lesion size expressed in mm, measured before removal) and several factors: age, sex, residence, sun exposure, presence of chemical burns, smoking habits. According to our results, UV radiation was identified as an important factor, as patients with prolonged exposure exhibited larger lesions. Other factors presented less significant correlations with the size of pterygium lesions.