Table 2 presents CYP1A1 genotypes of the pterygium and control groups. In the pterygium group, 50 (33.3%) were homozygous for the m1/m1 genotype, 22 (14.7%) were homozygous for the m2/m2 genotype, and 78 (52.0%) were heterozygous for the m1/m2 genotype. In the control group, 26 (52.0%) were homozygous for the m1/m1 genotype, 8 (16.0%) were homozygous for the m2/m2 genotype, and 16 (32.0%) were heterozygous for the m1/m2 genotype. There was a statistically significant difference between the CYP1A1 genotypes of the pterygium and control groups (p=0.035). This evidence concerns the gene CYP1A1 and pterygium.