In recent years, online radicalization has received increasing attention from researchers and policymakers, for instance, by analyzing online communication of radical groups and linking it to individual and collective pathways of radicalization into violent extremism. But these efforts often focus on radical individuals or groups as senders of radicalizing messages, while empirical research on the recipient is scarce. To study the impact of radicalized online content on vulnerable individuals, this study compared cognitive and affective appraisal and visual processing (via eye tracking) of three political Internet memes (empowering a right-wing group, inciting violence against out-groups, and emphasizing unity among human beings) between a right-wing group and a control group. We examined associations between socio-political attitudes, appraisal ratings, and visual attention metrics (total dwell time, number of fixations). The results show that right-wing participants perceived in-group memes (empowerment, violence) more positively and messages of overarching similarities much more negatively than controls. In addition, right-wing participants and participants in the control group with a high support for violence directed their attention towards graphical cues of violence (e.g., weapons), differentness, and right-wing groups (e.g., runes), regardless of the overall message of the meme. These findings point to selective exposure effects and have implications for the design and distribution of de-radicalizing messages and counter narratives to optimize the efficacy of prevention of online radicalization.