## 3 Results and Discussion  
### Effect of the Fcacis  
The experimental results revealed a significant difference in SSQ scores between subjects who navigated the 3D virtual store with and without the FACIS (F(1,46) = 8.954, \(p\) = 0.004). The SSQ scores of the subjects with the FACIS (SSQ = 20.570) were significantly lower than those of the subjects without the FACIS (SSQ = 32.880). This result shows that the FACIS can reduce the severity of cybersickness.  
The SSQ has three main categories for scoring cybersickness: nausea, oculomotor, and disorientation. Figure 8 shows that in the experimental environment of the 3D virtual store, regardless of whether the FACIS was enabled, the rate of oculomotor symptoms compared with other symptoms was the highest (with the FACIS: 61%; without the FACIS: 57%). By examining the oculomotor symptoms in detail, it was found that the subjects mainly experienced eye fatigue, an inability to see the picture clearly, and an  
\begin{table}
\begin{tabular}{p{142.3 pt} p{142.3 pt}} \hline \hline
**Procedure** & **Description** \\ \hline
1. Explanation & Before the experiment, each subject was given a copy of the operating instructions for the 3D virtual store, and an experimental assistant explained the experimental procedures and personally demonstrated the operation. \\ \hline
2. Familiarization & To familiarize the subjects with the 3D virtual store environment, before the experiment, the subjects were allowed to practice operating the device to understand how to navigate in the 3D virtual store. After practice, the subjects could start the experiment once they were familiar with the operation. \\ \hline
3. Start of the experiment & Before the formal experiment began, each subject had to input personal characteristic data and hardware types. First, the subjects completed the shopping experiment without the FACIS, and then they performed the shopping experiment with the FACIS one week later. A shopping list was issued for each purchase, and the products were randomly assigned. There were a total of 10 products on the shopping list, 2 of which were not on the list. Once the 10 items had been confirmed, the experiment was completed. \\ \hline
4. Filling out the questionnaire & After each experiment, the subjects had to fill in the SSQ to evaluate the performance of the FACIS. \\ \hline \hline \end{tabular}
\end{table}
Table 3: Experimental procedure for the 3D virtual store shopping.  
inability to concentrate. However, when the FCACIS was used, the oculomotor scores decreased significantly, as shown in Figure 8. This may be because when the FCACIS monitors the subject's reaction, if the CSSV exceeds 7.5, the FCACIS is activated; a warning, a blur filter, and an adjustment screen to narrow the field of view appear in the 3D virtual store, and the filter transparency gradually increases as the CSSV increases. Through FOV reduction, the discomfort caused by excessive operations is significantly reduced. This design allows the subjects to relieve the early stages of cybersickness, reducing eye fatigue. Possible side effects, such as an inability to see clearly and an inability to concentrate, are also relieved. Therefore, activating the blur filter and reducing the FOV in time relieves oculomotor symptoms, thereby reducing early cybersickness. The nausea score includes the score for inability to concentrate. When the inability to concentrate decreases significantly, the total score for nausea also decreases significantly.