This study investigates the effects of morning high-intensity light exposure (3000 lux) on the health of sand rats, a diurnal animal model. The results show that morning light treatment leads to improved daily rhythms in activity, blood glucose levels, and *per2* gene expression. Treated animals exhibited better metabolic health, including normoglycemia, improved glucose tolerance, lower body and heart weight, and reduced anxiety and depression-like behaviors. The findings suggest that high-intensity light exposure is crucial for proper circadian system function and overall well-being, highlighting the potential impact of low daylight exposure and artificial light at night on human health.

Carmel Bilu, Haim Einat, Paul Zimmet, Vicktoria Vishnevskia-Dai, Noga Kronfeld-Schor