The improvement of cataract-extraction techniques and the development of better materials and designs of intraocular lens (IOLs) have resulted in a better quality of vision and less complications. Implanting a traditional, spherical IOL to replace a cataractous lens adds to the positive spherical aberration of the cornea. Therefore, although a patient’s Snellen visual acuity may be good after implantation; functional vision may still be poor. Aspheric IOLs were recently designed to optimize image quality, by compensating the positive spherical aberration. Patients and methods: In this study, wavefront scan using OPD-scan II wavefront aberrometer was done preoperatively and postoperatively for 40 eyes divided into 2 groups. The aspheric group A which included 20 eyes implanted with Technis ZA9003 IOL. The spherical group B which included 20 eyes implanted with Sensar AR40e IOL. Internal ocular aberration was the mean concern in this study and was measured for 3 and 5 mm pupil diameters. Results: Eyes with the Technis ZA9003 IOL had significantly more negative internal spherical aberration postoperatively at 5 mm pupil diameter compared to the Sensar AR40e IOL. Strehl ratio showed no significant differences at 3 mm pupil diameter and a significant increase postoperatively in the Sensar IOL at 5 mm pupil diameter. Conclusion: A significant reduction in the spherical aberration after Technis ZA9003 IOL implantation was achieved.