## 4 Discussion  
The aim of this study was to examine the effects of wearing the three most common combinations of protective headgear in skiing (ski cap, ski cap and sunglasses, and ski helmet and ski goggles) on the timing of visual stimuli perception and adequate response when simulating on-the-slope situations. Additionally, the aim was to determine potential differences in reaction time for helmet users and non-users. The reaction speed to visual stimuli differed between different conditions of wearing protective headgear for both prior helmet users and non-users, regardless of the side from which the visual stimuli appeared. Likewise, in the interaction of two factors (the habit of wearing a helmet and different condition of headgear equipment), statistically significant differences were found in both groups for both sides of the visual stimuli source. When observing the results, it can be confirmed that the response time of the participants was the slowest when wearing a ski helmet and goggles combined, compared to the other tested conditions (ski cap, ski cap and sunglasses). The same can be stated for both prior helmet users and non-users. Furthermore, one of the most important findings related to determined differences in reaction time between helmet users and non-users, i.e., prior helmet users tended to react faster to the upcoming visual stimuli when wearing both a ski helmet and goggles. This is in the accordance with the stated hypothesis, and we confirmed that peripheral vision reaction time was better when the habit of wearing a ski helmet was developed. Similar findings regarding the influence of a habit of wearing a helmet on a sensory performance were determined in a study conducted by [PERSON] et al. [26]. In that study, localization of specific ski sounds was measured to determine differences between various tested conditions of wearing protective headgear but also to determine potential differences between helmet users and non-users. The results showed a significant difference in specific ski sounds localization when wearing a helmet vs. not wearing a helmet (\(p\) < 0.001). However, the habit of wearing a ski helmet did not affect performance (\(p\) = 0.89). On the other hand, when discussing the timing, i.e., the exact moment at which participants registered the sound stimuli, the results were also better when the participants were not wearing a helmet (\(p\) < 0.001). Furthermore, in that case, the results did depend on the habit of wearing a helmet (\(p\) < 0.05). This means that the decreased ability of sound identification that occurs because of helmets might be avoided with the regular usage of a ski helmet. The results obtained in our study also confirm the direct influence of a helmet-wearing habit on the timing of perceiving stimuli, but in this case the significant difference was found when testing the reaction time on the upcoming visual peripheral stimuli (\(p\) < 0.01). Helmet users tended to react faster (on average 0.04 s), which can directly relate to their better positioning in dangerous situations, helping them to avoid collisions with other skiers or falls on the ski slopes. Furthermore, [PERSON] et al. [17] conducted a laboratory testing procedure to measure the reaction time necessary to respond to a stimulus presented in the peripheral visual field. In their study, the lowest mean reaction time was measured for cap-only use (477.3 \(\pm\) 16.6), the same as in our study (mean reaction time for both groups were 0.29 s). The determined reaction time did not differ when wearing a helmet only (478.5 \(\pm\) 19.1, \(p\) = 0.911). On the other hand, reaction time was significantly longer when wearing both cap and goggles (514.1 \(\pm\) 20.8, \(p\) = 0.005) and both helmet and goggles (497.6 \(\pm\) 17.3, \(p\) = 0.017) when compared to cap-only use.