## 4 Discussion
In our sample, a significant increase was found with the CL wear in HOA RMS, primary coma RMS, primary spherical aberration Zernike term and secondary astigmatism RMS for both 3 and 5 mm pupils, but always reaching values within the range of variability of ocular aberrations defined for the healthy population using the same multi-diagnostic platform [40]. By increasing the pupil diameter, a trend to a change to negative primary spherical aberration was observed together with changes of small magnitude although statistically significant for the rest of the aberrometric coefficients, suggesting that the EDOF design allows a controlled induction of HOAs leading to a minimally pupil dependent depth-of-focus range. [PERSON] et al. [23] in a simulation study computing the through focus retinal image quality demonstrated that the EDOF CL design used in the current series deliberately induced multiple higher-order aberrations making the optical quality of the CL + eye system less susceptible to variations in the pupil, inherent ocular aberrations and lens decentration. The increase in ocular aberrations with the CL evaluated could be related to the initial reduction in visual acuity observed in the current series. [PERSON] et al. [41] found that more reduced visual acuity was present in healthy subjects with more levels of comakelike aberrations. Besides the impact on visual acuity, the increase in aberrations can also promote the perception of photic phenomena, such as glare, halos and starburst. For this reason, a self-developed questionnaire was used to ask patients about the frequency and level of bothersomeness of these three photic phenomena. A trend to an increase in the perception of photic phenomena with the CL wear was observed but in most cases occasionally and inducing mild bothersomeness. [PERSON] et al. [42] and [PERSON] et al. [43] used a validated questionnaire of quality of vision to analyze the impact of off-label multifocal CL fitting for myopia control, reporting the presence of a certain level of blurred vision, visual fluctuation, focus difficulty and photic symptoms. Specifically, [PERSON] et al. [43] reported a decrease in these photic symptoms after one month of CL use, except for halos. Our study showed a low incidence of glare and halos before and after CL wear, with no patient reporting the perception of moderate or severe glare or halos. These data are consistent with those obtained by [PERSON] et al. [34], who also found a low incidence of halos and glare with an EDOF CL. Almost half of the sample of patients reported the perception of starbursts before fitting (46.7%), and after 30 days of CL wear (46.2%), most of them referred to this photic phenomenon as mild or minimally bothersome. Other changes with the EDOF CL were also investigated, such as pupillary and anatomical modifications. In the present study, a significant decrease in pupil size measured under photopic conditions was detected, although the change was small in magnitude (0.19 mm) and of potentially low clinical relevance. This may be due to the contribution of several factors, such as the inherent variability of the measurement procedure, changes in the emotional or mental status or even the variability associated with the physiological pupillary hyppus [44]. Changes in visuocortical activity are not systematically related to pupil size modifications [45]. Therefore, it is difficult to confirm if this minimal pupillary change is associated with the EDOF CL wear, with more studies being necessary. Concerning keratometry, no significant changes were detected with the CL wear. The clinical trials carried out by [PERSON] et al. [16] and [PERSON] et al. [21] evaluated the morphological changes of the cornea after prolonged use of myopia control CLs, without obtaining variations in either keratometry or pachymetry. These results are consistent with those obtained in our study.