An eyeglass lens prepared using a resin composition containing m-xylylene diisocyanate, a polythiol compound, and an ultraviolet absorber, wherein the ultraviolet absorber contains at least a formula compound selected from the group consisting of 2-(4-butoxy-2-hydroxyphenyl)-2H-benzotriazole and 2-(4-ethoxy-2-hydroxyphenyl)-2H-benzotriazole and a formula compound consisting in 2-(2H-benzotriazol-2-yl)-6-(1-methyl-1-phenylethyl)-4-(1,1,3,3-tetramethylbutyl)phenol and the M value represented by formula is greater than 1.40 but less than 3.20; M value = λ 2 − λ 1 × A 2 / A 1 × W 2 / W 1 In formula, λ 1 represents the maximum absorption wavelength of a compound represented by formula in the ultraviolet-visible absorption spectrum of a chloroform solution in which the concentration of a compound represented by formula is 10 weight ppm; λ 2 represents the maximum absorption wavelength of a compound represented by formula in the ultraviolet-visible absorption spectrum of a chloroform solution in which the concentration of a compound represented by formula is 10 weight ppm; A 1 represents the absorbance at the maximum absorption wavelength of a compound represented by formula in the ultraviolet-visible absorption spectrum of a chloroform solution in which the concentration of a compound represented by formula is 10 weight ppm; A 2 represents the absorbance at the maximum absorption wavelength of a compound represented by formula in the ultraviolet-visible absorption spectrum of a chloroform solution in which the concentration of a compound represented by formula is 10 weight ppm; W 1 represents the amount in parts by weight of a compound represented by formula when the total of the m-xylylene diisocyanate and the polythiol compound is 100 parts by weight; W 2 represents the amount in parts by weight of a compound represented by formula when the total of the m-xylylene diisocyanate and the polythiol compound is 100 parts by weight. In formula, λ 1 represents the maximum absorption wavelength of a compound represented by formula in the ultraviolet-visible absorption spectrum of a chloroform solution in which the concentration of a compound represented by formula is 10 weight ppm; λ 2 represents the maximum absorption wavelength of a compound represented by formula in the ultraviolet-visible absorption spectrum of a chloroform solution in which the concentration of a compound represented by formula is 10 weight ppm; A 1 represents the absorbance at the maximum absorption wavelength of a compound represented by formula in the ultraviolet-visible absorption spectrum of a chloroform solution in which the concentration of a compound represented by formula is 10 weight ppm; A 2 represents the absorbance at the maximum absorption wavelength of a compound represented by formula in the ultraviolet-visible absorption spectrum of a chloroform solution in which the concentration of a compound represented by formula is 10 weight ppm; W 1 represents the amount in parts by weight of a compound represented by formula when the total of the m-xylylene diisocyanate and the polythiol compound is 100 parts by weight; W 2 represents the amount in parts by weight of a compound represented by formula when the total of the m-xylylene diisocyanate and the polythiol compound is 100 parts by weight.