This study investigates the potential of near-infrared light (NIR) to modulate meningeal lymphatic vessels (mLVs) and improve cognitive function and pathology in aged and Alzheimer's disease (AD) mouse models. NIR light, applied transcranially, was found to enhance mLVs drainage, reduce amyloid beta (Aβ) deposition, neuroinflammation, and neuronal damage. Transmission electron microscopy and RNA sequencing revealed improvements in mitochondrial metabolism and cellular junctions of meningeal lymphatic endothelial cells (mLECs). The results suggest that NIR light treatment can improve cognitive function by strengthening mLVs' scavenging ability through restoring mLEC function, offering a potential strategy for neurodegenerative diseases.This study investigates the potential of near-infrared light (NIR) to modulate meningeal lymphatic vessels (mLVs) and improve cognitive function and pathology in aged and Alzheimer's disease (AD) mouse models. NIR light, applied transcranially, was found to enhance mLVs drainage, reduce amyloid beta (Aβ) deposition, neuroinflammation, and neuronal damage. Transmission electron microscopy and RNA sequencing revealed improvements in mitochondrial metabolism and cellular junctions of meningeal lymphatic endothelial cells (mLECs). The results suggest that NIR light treatment can improve cognitive function by strengthening mLVs' scavenging ability through restoring mLEC function, offering a potential strategy for neurodegenerative diseases.