The impacts of situational visual impairment on usability of touch screens

Using a touchscreen mobile device while walking in sunlight glare limits the visual attention. This situational visual impairment could affect the usability of these devices. This work focuses on the user interaction in situational visual impairment regarding touch gestures and no-visual feedbacks. We performed two user studies. In the first study, we modified the user interface of the two most used applications, phone calling and text messaging, using touch gesture and audio feedback while these features were not used before. Then a user study performed to extract the user preferences of modified applications in visual impairment situation. Our findings indicate that participants preferred gestures, but did not clearly indicate a preference for audio feedback. In the second study, we employed the computational evaluation to explore the distinctions between the made gestures by individuals in two different situations: with and without visual impairment. The outcomes show that in situations with visual impairment: (1) the people draw bigger and broader gestures, (2) there is higher error in features related to geometric shape, (3) familiarity of the user with gestures changes the speed and time for drawing them, and (4) there is not a critical distinctive conduct in how to apply strokes. The user interaction in situational visual impairment could be improved using touch gesture without audio feedback. This situation needs a wider area to make the gestures.