## 3 Results  
Figure 2 shows the mean radial profiles along the axis of symmetry of the lens (shown in Figure 1) obtained from 10 measures for each of the Acunex IOLs used in the study. The monofocal IOL (AN6) is represented by a solid red line, while the multifocal models are represented by solid green (AN6V) and blue (AN6 VM) lines. The left part in Figure 2 corresponds to the lower half of the lens (containing the near power zone) when it is positioned for implantation (with the add at the bottom), while the right part corresponds to the upper half of the lens (containing the far power zone). As can be seen from Figure 2, the three IOLs have similar far power distribution (right side of the graphs), with slight differences towards the periphery of the optics. The monofocal model shows a radial power equal to the nominal power for around the central 2 millimeters of the IOL optic, with a posterior decrease in refractive power towards the IOL periphery, consistent with a negative spherical aberration. The multifocal models are more constant in the far power distribution (right side of the graphs in Figure 2), with almost the same radial power as the nominal power up to the periphery of the far portion of the optics. In the case of multifocal models, it can be seen from Figure 2 that the far power of the lens does not exactly restrict to the right side of the graphs, but extents to around the first 0.12 mm of the left side, that is, the near zone begins 0.12 mm below de IOL center. This fact is in perfect concordance with the central notch in the near addition segment shown in Figure 1.  
Figure 1: Image of the Acunex multifocal lens measured on the optical bench (**left** side). The near power zone is located at the bottom, while the distance power zone is at the top and centered within the notch. The vertical dashed line symbolizes the axis of symmetry, along which data was collected to illustrate power profiles. The cuvette with the lens inside in measurement position (**right**). The left side of the graphs (near vision) shows significant differences between the monofocal and multifocal models. As mentioned above, for the AN6V and AN6 VM, the increase in power for near vision occurs not exactly from the center of the lens (x = 0 mm), but approximately 0.12 mm below the optical center (x = \(-\)0.12 mm), with a \"two-step behavior\": an initial increase of half the addition in power from approximately x = \(-\)0.12 mm to x = \(-\)0.50 mm, and a posterior increase from approximately x = \(-\)0.50 mm to x = \(-\)0.75 mm, until achieving the maximum addition. For the three measured nominal powers, the power profile corresponding to the near vision has a parallel behavior between low (AN6V) and high (AN6 VM) addition multifocal models, being the distance between both lines of 1.50 D (exactly the difference in addition power between both models). It seems that the +10.00 D IOL maintains a constant addition value all over the near part of the optics (see the parallelism between the AN6V and AN6 VM IOL power profiles and the +1.50 D addition and +3.00 D additions dashed lines in the left side of the plot), whereas the +30.00 D IOL shows a decrease in addition power towards the periphery of the near segment (see the difference of almost 1 D between addition at x = \(-\)0.63 mm and addition at x = \(-\)2.25 mm in the left side of the plot). The +20.00 D IOL shows a behavior between that of the +10.00 D and the +30.00 D IOLs. Regarding aberrometric profiles, Figure 3 shows primary spherical aberration variation with optical zone diameter, whereas vertical coma is depicted in Figure 4 (primary vertical coma and secondary vertical coma).