The SPARKLE study aims to investigate whether light therapy can be used to reduce cancer-related fatigue in Hodgkin lymphoma and diffuse large B-cell lymphoma survivors. Forty to sixty percent of these survivors experience moderate to severe fatigue since their diagnosis. This fatigue has an impact on their daily functioning and impacts quality of life. Previous pilot studies showed promising effect of light therapy as a treatment for this complaint. The SPARKLE study is a multicenter randomized controlled trial to replicate these findings. Besides this replication, we also aim to investigate the association between circadian rhythms and fatigue in these survivors. The data collection for this study is complete. In total, 166 survivors participated. At this moment, we analyze the data and write manuscripts with the results and conclusions.