Do energy drinks cause your pupils to dilate?

Energy drinks have been known to cause a slight dilation of the pupils, but this effect is usually temporary and not significant. The dilation is caused by the stimulant caffeine, which is often a major component of energy drinks. Caffeine can stimulate the sympathetic nervous system, which controls the pupil's size. Dilated pupils are also associated with increased arousal and alertness, which are common effects of caffeine.