Blue light with a wavelength of 380-500 nm is the most dangerous part of the visible spectrum for the retina.
Short-term exposure to high intensity blue light causes photon absorption, leading to the production of reactive oxygen species (ROS) and free radicals. These molecules are highly reactive and can damage cellular structures, including proteins, lipids and DNA. The consequence of this damage is weakening of the cell function, which can lead to premature cell ageing and apoptosis, i.e., programmed cell death. Controlled studies in primates, which have structurally similar eyes to humans, have shown that with reduced levels of macular pigments, which naturally filter blue light and neutralise free radicals, the first signs of age-related macular degeneration (AMD) can appear as early as mid-normal age, which is equivalent to about 35 years in humans (instead of the typical age of 65+ years). These findings underscore the importance of protecting the retina from overexposure to blue light, as its cumulative effects can lead to the early development of AMD, the leading cause of vision loss in older adults.
