The debate about whether making a risky choice is based on a weighting and adding process has a long history and is still unresolved. To address this long-standing controversy, we developed a comparative paradigm. Participants' eye movements in 2 risky choice tasks that required participants to choose between risky options in single-play and multiple-play conditions were separately compared with those in a baseline task in which participants naturally performed a deliberate calculation following a weighting and adding process. The results showed that, when participants performed the multiple-play risky choice task, their eye movements were similar to those in the baseline task, suggesting that participants may use a weighting and adding process to make risky choices in multiple-play conditions. In contrast, participants' eye movements were different in the single-play risky choice task versus the baseline task, suggesting that participants were not likely to use a weighting and adding process to make risky choices in single-play conditions and were more likely to use a heuristic process. We concluded that an expectation-based index for predicting risk preferences is applicable in multiple-play conditions but not in single-play conditions, implying the need to improve current theories that postulate the use of a heuristic process.