With the increasing prevalence of electronic devices in our lives, many people spend their entire day working in front of computers and smartphones. So, what kind of harm does prolonged exposure to the harmful blue light emitted by these electronic devices have on our physical health?
What is Blue Light?
Light is actually a type of electromagnetic wave, and the part that can be perceived by the human eye is called visible light. The wavelength of visible light ranges from 400 nanometers to 760 nanometers, with ultraviolet light below 400 nanometers and infrared light above 700 nanometers.
Blue light refers to the blue light waves with wavelengths between 380 nanometers and 500 nanometers. It is also known as high-energy visible light, which is the most powerful spectrum band of visible light. Due to its high energy, according to the laws of physics, blue light has a wider scattering range than any other visible light. In addition to the sun, many artificial light sources also emit blue light, which is the main source of harm to the human body.
Sources of artificial blue light include smartphones, tablets, computer screens, LED lights, and bathroom heaters, among others.
Blue Light Causes Vision Decline
When blue light enters the back of the eye, it does not focus directly on the retina but between the retina and the lens. This exacerbates chromatic aberration and visual blur, causing excessive tension in the eye muscles and blood supply, leading to increased fatigue. Therefore, prolonged exposure to blue light causes significant eye fatigue and varying degrees of vision decline, which is more pronounced in minors.
Blue Light Can Cause Macular Degeneration
Many people know that ultraviolet and infrared rays are usually absorbed by the cornea and lens and can cause damage to the eyes, but they generally do not come into contact with the retina. However, blue light can penetrate the cornea and lens and reach the retina, causing chronic damage and degeneration to the retinal photoreceptors. If the macular area is exposed to blue light for a long time, this chronic and cumulative damage will ultimately increase the risk of macular degeneration and even permanent vision damage. Older adults who are exposed to blue light for long periods of time are more likely to develop age-related cataracts and other eye diseases.
Blue Light Can Cause Eye Damage After Cataract Surgery
The natural lens of the human eye has a yellowish tint, which filters blue light to protect the retina. However, after cataract surgery and lens replacement, the eye loses this natural barrier, and blue light can directly reach the retina, causing damage to the retinal pigment epithelial cells.
Blue Light Can Disrupt Circadian Rhythm
Blue light signals our body that it is not yet time to sleep. The pineal gland in our brain secretes melatonin, an important substance in regulating the body's circadian rhythm and initiating sleep. Under blue light exposure, the secretion of melatonin is inhibited, affecting the normal circadian rhythm of the body, leading to decreased sleep quality and disrupted biological clocks.
In conclusion, prolonged exposure to blue light from electronic devices can have various negative effects on our vision, retina, and overall health. It is important to take measures to protect our eyes from excessive blue light exposure, such as using blue light filters on screens or reducing screen time before bed.
