If the XPA A23G and XPD codon 751 polymorphisms, like in other tissues, are correlated with the DNA repair capacity of NER in the conjunctiva and cornea, the result of polymorphisms of XPA A23G and XPD codon 751 not associated being with pterygium formation may suggest that the NER system might not play a role in pterygium formation; however, more evidence is required to support this theory. This evidence concerns the gene ERCC2 and pterygium.