The post highlights a 2025 study from Scientific Reports showing that longer wavelengths of sunlight (beyond 700 nm) penetrate human tissue, boosting mitochondrial function and vision, a finding supported by experiments using infrared-sensitive cameras to visualize light transmission through the thorax and hands.

This research, led by Glen Jeffery, builds on decades of photobiology work, revealing that modern LED lighting (lacking these wavelengths) may harm mitochondrial performance and cardiovascular health, challenging the widespread adoption of LED technology in homes and cities.

Evidence from controlled trials with 850 nm LED exposure showed a 16% improvement in tritan color contrast thresholds, suggesting systemic health benefits from sunlight’s infrared spectrum, even when eyes are shielded, aligning with evolutionary reliance on natural light.