Reflexivity - critical awareness of methodological choices, assumptions, and positionality - is essential for robust research, particularly when data are context-dependent and interpretive. It helps address bias, privacy, fairness, and societal impact. We focus on these human aspects in eye tracking (ET), and on the researchers who design, interpret, and deploy these systems. We choose ET as a leading example, given the very important impact of researchers: ET data acquires meaning only through experimental design, theoretical assumptions, and analytic pipelines. Small methodological decisions can significantly shape conclusions. As ET integrates with AI and real-world applications, the researcher's role becomes even more consequential. Yet privacy-preserving techniques remain limited, despite eye-tracking data revealing sensitive information such as identity, health, or cognitive states. Adopting such techniques requires researchers' critical reflection on privacy and ethics, but reflexive practices are rarely formalised in ET. We introduce two complementary tools developed with over 60 researchers: REFLECT, a qualitative questionnaire, and SPERET, a validated psychometric scale. REFLECT enables in-depth questioning of privacy and ethics in small teams, while SPERET enables community-level comparisons. Using REFLECT, we reveal recurring assumptions about generalisability and competing values in handling sensitive data that explain limited adoption of privacy techniques. SPERET operationalises these findings and consistently measures reflexivity. Together, our tools provide empirical insights into ethical reasoning and concrete instruments to promote more privacy- and ethics-conscious research practice at individual and community levels.