Photochemically-induced retinal injury is caused by the absorption of light by photoreceptors in the retina. Photoreceptors such as rod cells & cone cells convert light into electrical signals in the eye via the chemical process where Rhodopsin (an extremely light-sensitive receptor protein influential to visual phototransduction) & Blue Light collide.
Normally, when light hits Rhodopsin, Rod & Cone cells bleach and becomes ineffectual until they have recovered through a metabolic process (approximately 30 minutes) called Wald’s visual cycle. This visual cycle is the biological process which converts photons, such as electromagnetic radiation (UV light & Blue Light) into electrical signals in the retina.
Blue Light & Retina Damage
Photoreceptor cells are noticeably more sensitive after this process and become responsive to light before they are ready. Damage to Photoreceptors can occur when the retina is subjected to a Blue Light wavelength of 400 – 500 nanometres. Blue Light Retina damage can occur within a few minutes of exposure to Blue Light at 408 nanometres. This is enough to cause permanent death of photoreceptors and lesions of the retinal pigment epithelium.
The catch is, Photoreceptor cells need retinal molecules to sense light. When retinal molecules are exposed to Blue Light, a reaction is triggered in which the retinal releases poisonous chemical molecules that dissipate the photoreceptor cell membranes.
Photoreceptors cannot regenerate once they die, their fate is irreversible. Research has proven that retinal generated toxicity by Blue Light is universal. Blue Light can kill any cell, such as cancer cells, heart cells, and neurons, as long as it is in the presence of retinal molecules. Blue light has no effect on these cells without retinal molecules and no such destructive activity is present with other light, such as yellow, red or green light.