# High-Order Aberrations: A Key Factor in Accommodative Dysfunctions
## 4 Discussion  
Accommodative dysfunctions affect a significant number of subjects, leading to symptoms and affecting performance when working and studying. Despite the wide range of prevalences, insufficiency of accommodation is the accommodative dysfunction with the highest prevalence reported in the literature, affecting between 2% and 61.7% of the population [17]. In the present study, insufficiency of accommodation was also the most prevalent accommodative dysfunction. Given the close relationship between ocular aberrations and accommodation, this study aimed to investigate how wavefront aberrations change during accommodation and disaccommodation for different accommodative dysfunctions. Several studies reported that the RMS HOA value tends to maintain or decrease its value up to around 3.00 D of accommodation [2; 4; 18]. [PERSON] et al. [4] found the maximum optical quality at around 2.50 D of accommodation. As a result of this accommodative demand, the RMS HOAs increase. In our study, a slight decrease in RMS HOAs was observed in the control group, reaching the best optical quality at 2.45 D of accommodation and increasing at 4.73 D. The same tendency was observed in subjects with INFA, with the 3 rd-order aberrations responsible for this increase in the 4.73 D stimulus. The changes within the INSA group were not significant in any order, neither during accommodation nor residual accommodation. Changes in ocular aberrations during accommodation have been reported as a mechanism to control the direction of the accommodative response [2; 5]. If subjects do not have significant changes in ocular aberrations, the accommodative process may be affected and they may have lower accommodative responses. After analyzing each RMS order, a statistically significant decrease was observed in the 4 th and 6 th orders in subjects with EA. Subjects with high accommodative responses may benefit from improved ocular optical quality. As the accommodative system adjusts to achieve the best retinal image quality, these subjects may over-accommodate, leading to excessive accommodation. The SWD group experienced an increase in RMS HOA for the 2.45 D and 4.73 D stimuli. This decline in ocular optical quality may explain the symptoms reported by these subjects, as the retinal image is more degraded, resulting in blurred vision, headache, or eye strain. The SWD group demonstrated difficulty in returning to their initial state after accommodation, with poorer ocular optical quality than before. This difficulty may be attributed to the challenges in returning to the initial accommodative state, as the crystalline lens is primarily responsible for most of the ocular aberration changes during accommodation due to its biometric changes [19; 20; 21]. The pattern of changes in ocular aberrations appears to change differently among the groups of accommodative dysfunctions. The visual system may interpret different blur patterns caused by changes in ocular aberrations, impacting accommodation accuracy. The shape and morphology of the crystalline lens, especially in the nucleus thickness [22], change during accommodation [23; 24], and the way they change may be different in some individuals, resulting in distinct changes in ocular aberrations and consequently affecting the accommodative response. On the other hand, these differences found in the changes in ocular aberrations with accommodation may be a consequence of the accommodative dysfunctions. As the structure of the lens defines its physiological function [23], it would also be interesting to study the lens capsule and its epithelial cells, as well as the lens fibres and the zonules of these subjects. The SWD group exhibited noticeable instability in optical quality, with a significant increase in the microfluctuations of the RMS HOAs during and after accommodation, i.e., in residual accommodation.