The abilities of visual perception are often misunderstood, with errors occurring more frequently than is often realised. The aim of the research was to investigate the visual error phenomenon of change blindness. An experiment using the flicker task paradigm explored the effects of fatigue, music presence, age and sex as influencing factors affecting task performance. Performance was measured via analysis of mean reaction times for correct responses. The sample comprised 60 participants (m=29, f=31), who fell into one of three age categories: 18-34 (n=32), 35-54 (n=18) & 55+ (n=10). Findings revealed that sleep deprivation had a negative impact on performance, as did increased age. Presence of music was also shown to have a positive significant impact, but only for the group of participants who reported feeling more fatigued than usual. Results verify the importance of sleep for attention related tasks, and real-world implications concern issues such as driving ability.