Head-worn display technology has been rapidly developing, and researchers have suggested that such devices could be used to improve patient monitoring in clinical settings. However, the use of these devices can be affected by perceptual and attentional issues, particularly when the wearer is under high workload. This study investigated the effect of a manual task load and display eccentricity on participants’ ability to detect stimulus changes on Google Glass. It was hypothesised that due to attentional load, accuracy of detection would be better when the participant was completing no manual task compared to a low load task, and better for a low load task compared to a high load task. It was further hypothesised that due to the design characteristics of Google Glass, participants would perform better when the display was at a near versus far eccentricity from the primary task. The experiment was operationalized by having participants (N = 53) complete a sewing task at varying degrees of difficulty, while maintaining the Google Glass display at a certain angle. Accuracy was measured based on the percentage of stimulus changes participants correctly detected. Accuracy of detection was worse when participants were completing the low load task than the no load task, however no difference was found between the low load and high load tasks. A difference was also found between eccentricity conditions, with participants performing worse when the Google Glass display was far compared to near the primary task. These findings support previous research of attentional load and identify an effect of manual task load. This study can inform further research into modern head-worn displays, specifically identifying weaknesses that can arise when using the device to capture attention.