The study on the magnification of the clear acrylic resin in prosthetic dentistry is important but lacking. Hence, this research aimed to investigate the magnification of the iris in the ocular prosthesis with various thicknesses of clear heat cure acrylic resin. A total of 60 ocular prostheses were divided into six groups with various thicknesses of clear heat cure acrylic resin over the iris; T0 (control): no acrylic resin, T1: 2, T2: 4, T3: 6, T4: 8, and T5: 10 mm of clear acrylic resin over the iris. Each ocular prosthesis was manufactured from white acrylic, with a 10.250 mm iris. Then, the clear heat cure resin was placed over the iris, cured, then polished. The final diameter of the iris was measured with a vernier caliper. The sizes of the iris were compared among various groups using one-way ANOVA, and a significant level was chosen at p value = 0.01. The mean sizes of iris were T0 = 10.25, T1 = 10.92, T2 = 11.26, T3 = 11.91, T4 = 12.75, and T5 = 13.43 mm. The size of the iris was significantly different among the group (p < 0.0001). The magnification of the iris for different groups was 1.06 for T1, 1.10 for T2, 1.16 for T3, 1.24 for T4, and 1.31 for T5. The magnification of the iris increased as the thickness of clear heat cure acrylic resin over the iris is increased on the ocular prosthesis.