A complex intraocular lens (IOL) design involving numerous uncertain variables is proposed. We integrated a genetic algorithm (GA) with a freeform surface lens by using CODE V optical design software to design a multifocal IOL for the human eye. We mainly used a freeform surface lens of acrylic material in the initial crystalline state to enhance image sensing quality; therefore, we used the internal human eye model in the software. The proposed optimization algorithm employs a GA method to optimally simulate the focusing function of the human eye; in this method, the thickness and curvature of the anterior lens and the posterior part of the IOL were varied. We performed a comparison of the proposed GA-designed IOLs and those designed using a CODE V built-in optimization algorithm for the hyperopia 300 degree condition of the human eye. When the pupil entrance was 6 mm, the proposed IOL design improved the RMS of the spot diagram by approximately 11.99 and 10.65% for the human eye to object distances of 35 cm and infinity, respectively. Moreover, the modulation transfer function (MTF) was improved by approximately 5.06 and 15.06% for distances of 35 cm and infinity at a spatial frequency of 15 cycles/mm, respectively.