## 4 Discussion  
UN, a neurobehavioral disorder, can occur as a result of neurodegenerative diseases [2], tumors [20], trauma [21], and stroke [22], where the brain ignores or fails to perceive information about half of the visual field. The severity of the disorder is significant, as it can result in a complete lack of attention to all types of stimuli occurring on the affected side of the body, placing not only the individuals but also those around them at risk in daily life. Even patients with UN may not recognize problems with the ability to recognize objects, making diagnosis difficult [23], and highlighting the importance of accurate screening and diagnosis for patients who plan to return to daily life through rehabilitation and treatment. The usefulness of the apple cancellation test, a tool for the diagnosis of UN, has received recent attention; however, the authors of this study found that the criteria for the correction of visual acuity before the test are unclear. Therefore, in this study, the authors analyzed the effect of different conditions for the correction of visual acuity on the results of the apple cancellation test. The aim was to establish guidelines regarding the correction of visual acuity for professionals in this field to assist in the accurate interpretation of results. The frequency of subjects diagnosed with UN using the apple cancellation test under three different conditions for the correction of visual acuity is shown in Table 1. Regardless of the type of UN, a positive diagnosis was made in eight cases (42.11%) before visual correction, in four cases (21.1%) with correction using glasses for the correction of distance visual acuity, and in two cases (10.1%) with correction using glasses for the correction of near visual acuity. In other words, the frequency of positive diagnosis of UN shows a significant decrease when the correction of visual acuity is achieved by wearing glasses for the correction of distance or near visual acuity compared to no correction of visual acuity. In addition, we performed an analysis to determine whether there were differences in the number of correct responses in the apple cancellation test under three different conditions for the correction of visual acuity (Table 2). The mean number of completely formed apples correctly marked by the subjects, which were placed on the right and left sides of the test sheet, increased in the order: before correction of visual acuity, with glasses for the correction of distance visual acuity, and with glasses for the correction of near visual acuity. According to the results of the post hoc analysis, an increase in the number of correct responses was observed with the use of glasses for the correction of distance visual acuity compared with pre-correction, but without statistical significance, whereas the number of correct responses showed a significant increase when wearing glasses for the correction of near visual acuity compared to before visual correction (\(p\) < 0.05). In addition, the authors performed an analysis to determine whether there were differences in the time spent completing the apple cancellation test depending on the type of glasses used for the correction of visual acuity (Table 3). The time spent in determining the completely formed apples varied depending on the conditions for the correction of visual acuity, which was significantly shortened when wearing glasses for the correction of near visual acuity (\(p\) < 0.05). Refractive error is a common condition that can easily cause the deterioration of visual acuity, as the eye is unable to focus an image onto the central fove