As we know, light is a form of electromagnetic radiation. The portion detectable by the human eye is called visible light, with wavelengths typically ranging from 400 to 760 nanometers. Wavelengths below 400 nm are ultraviolet rays, while those above 700 nm are infrared rays.
Blue light refers to blue rays with wavelengths between 380 and 500 nanometers, also known as high-energy visible light. It is the most energetically intense spectral band within the visible spectrum.Due to its high energy, blue light scatters more widely than any other visible light according to Rayleigh scattering. In nature, besides the sun, many artificial light sources also emit blue light. It is precisely this artificial "blue light" that poses the greatest harm to human health.
Sources of artificial blue light: Mobile phones, tablets, computer screens, LED lights, bathroom heaters, and similar devices all emit blue light, representing the most common artificial sources today.
Blue light causes vision deterioration
When blue light enters the eye, its focal point falls not directly on the retina but between the retina and the lens. This exacerbates chromatic aberration and visual blurring, causing excessive strain on the eye muscles and increased blood supply to the eye, thereby intensifying fatigue. Consequently, prolonged exposure to blue light leads to significant eye fatigue and varying degrees of vision decline.These effects are more pronounced in minors.
Blue light can cause macular degeneration
Many people know that ultraviolet and infrared rays are typically absorbed by the cornea and lens, causing eye damage, but they generally do not reach the retina.Blue light, however, can penetrate the cornea and lens to reach the retina, causing chronic damage and degeneration of retinal photoreceptors. Prolonged exposure of the macular region to blue light can lead to cumulative damage, ultimately increasing the risk of macular degeneration and potentially causing permanent vision loss. For the elderly, years of cumulative blue light exposure significantly heighten the likelihood of developing age-related cataracts and other eye diseases.
Blue light can cause post-cataract surgery eye damage
The human lens naturally has a yellowish tint that filters blue light to protect the retina. After cataract surgery and lens replacement, the eye loses this natural barrier, allowing blue light to directly reach the retina and damage retinal pigment epithelial cells.
Blue light disrupts the body's circadian rhythm
Blue light signals to our bodies that it is not yet time to sleep.Melatonin, secreted by the pineal gland in the brain, is a crucial regulator of the body's circadian rhythm. It initiates sleep. Exposure to blue light halts melatonin secretion, disrupting the body's natural clock. This leads to reduced sleep quality and circadian rhythm disorders.