The VR application involves three real-life scenarios. During the first scenario the user needs to crossthree busy roads using pedestrian traffic lights designed using different schemes to indicate the GO and STOP commands. In the first case, symbols (octagon and arrow) are used, in the second case the words "GO" and "STOP" were utilized and in the third case the use of a walking or stationary human figurewere used (see figure 1).The second scenarioincludes a virtual clothing store (see figure 2) where cloth coloursare presented using dedicated symbols on labels or using text labels or using audio, activated using proximity sensors.
The third scenario involves the purchase of fruits and vegetablesof specific color in a virtual supermarket (figure 3). In this case the colour/type of different fruits is indicated through dedicated symbols and labels that help the user to distinguish fruits.During the experiments users were requested to cross the roadsusing the three types of pedestrian traffic lights in order to be transferred to the cloth store scene where the user is requested to select a red, a blue and a yellow shirt in the right order.
Once the cloths are selected the user is transferred to the supermarketwhere the task is to select a red apple and a green lemon. In all cases different types of achromatic vision disorders (i.e. protanopias, deuteranopia, tritanopia) are simulatedso that the tasks are performed through the eyes of achromatopsiapatients. The visualization of the VR environment was done using an Oculus Rift headset and the interaction was carried out using a game controller.