Interactive visualizations are often built to draw the eye towards pertinent information with attention-grabbing pops of color and patterns. These techniques, though helpful in engaging the average user and nudging them towards important information, can be harmful to users with photosensitive epilepsy, who may experience seizures when exposed to content with flashes, transitions to and from saturated red, or repeated patterns. In this paper, we explore three case studies of interactive visualizations created without malicious intent yet capable of producing seizure-inducing sequences through interaction alone. Based on these case studies as well as relevant related literature, we contribute a set of simple recommendations to help visualization designers and developers avoid accidentally creating interactive visualizations with the potential to cause seizures.