The effect of blue light on the eyes
- Aim: The aim of this article is to highlight the potential hazards as well as the damages caused by blue light to the eyes.
Keywords: Blue light, Ultraviolet rays, visible light spectrum.
What is Blue light?
Sunlight is made up of visible and invisible rays. The visible rays (ROYGBIV), comprises of red, yellow, orange, green, blue light rays, while the invisible rays before the red spectrum are called infrared rays and those after the blue spectrum are called ultraviolet rays.
Rays on the red end of the visible light spectrum have longer wavelengths while those of the blue end have shorter wavelengths.
Scientifically, light rays that have long wavelengths contain less energy and those with shorter wavelengths have more energy. That is why the rays with the shorter wavelengths with high energy are considered to be dangerous to the eyes.
Blue light are the rays ranging from 380 to 500nm in the visible spectrum; natural blue light is everywhere around us. It is what makes the sky looks blue.
However, artificial blue light, found in things like computer, flat screen televisions, LED lights, bulbs can be harmful to the eyes because the emit high amounts of very strong energetic blue light waves which flickers (flashes) on the eyes causing eye fatigue.
EFFECTS OF BLUE LIGHT TO THE EYES
- HYPEROPIA:
Blue light have been found to aggravate hyperopia, since it travels undeviated through the cornea, lens and even to the back of the retina, causing images to be formed behind the retina, increasing blurred vision at near.
- COMPUTER VISION SYNDROME:
Blue light emitted by electronic device screens can lead to a condition called ‘computer vision syndrome’, with symptoms like dry eye, irritated eyes, blurred vision, eye fatigue and headaches.
This is because the blinking frequency becomes reduced and affects lubrication of the eyes over a long period of time, causing redness irritation blurring, eye fatigue and sometimes headaches.
- DIGITAL EYE STRAIN:
Blue light contributes to digital eye strain; this is because it scatters more easily than visible light and are not focused on the retina thereby reducing contrast and causing eye strain.
- AGE RELATED MACULAR DEGENERATION:
Blue light exposure may increase ones risk of macular degeneration because the eyes are not very good at blocking blue light, so virtually all blue light except ultraviolet rays passes through the cornea, lens and reaches the retina, when this blue light hits the retina, it’s high energy mixes with oxygen creating a destructive force that gradually destroys the sensitive photoreceptive cells and retinal pigment epithelium leading to age related macular degeneration.
- INSOMNIA:
Blue light does not only affect the eyes, it also affects the body system. This is noticed when using smart phones before bedtime; because blue light has a short wavelength which affects the sleep inducing hormone ‘melatonin’ more than any other of the wavelengths causing a change in sleep pattern.
The persistent change in sleep pattern may eventually lead to a shift in the body’s natural clock ‘circadian rhythm’ which is responsible for waking up and sleeping.
WHO ARE MORE AT RISK TO THE EFFECTS OF BLUE LIGHT
- Children are more at risk to the effects of blue light since they are exposed to digital devices at an early age.
- They have shorter arms and are always doing near work (making them very close to emission from these digital devices)
- Children have crystal clear crystalline lenses which blue light can easily pass through.
WHAT CAN YOU DO TO AVOID THE EFFECTS OF BLUE LIGHT
If constant exposure to blue light from smart phones, tablets and computer screens is an issue, there are a few ways to decrease exposure to blue light.
?? Reducing Screen Time
Try to decrease the amount of time spent in front of these screens by taking frequent breaks to give your eyes some rest for example use the ‘20/20/20 Rule’ which means look away from your digital device every 20 minutes for 20 seconds about 20 feet away. This helps to refocus and avoid CVS and eye strain.
?? Filters
Screen filters are available for smart phones, tablets and computer screens. They decrease the amount of blue light given off these devices that cold reach the retina.
?? Computer Glasses
Computer glasses with ‘yellow tinted lenses’ that block blue light can help ease computer digital eye strain by increasing contrast e.g bluetech lenses.
?? Anti-reflective lenses
This lenses reduces glare and increase contrast and also block blue light from the Sun and digital devices (i.e digital eye strain lenses)
?? Use Good ambient Lighting
Reducing the light on your device help avoid high contrast and reduce glare. Also avoid using a device in complete darkness.
?? Do not use your digital device an hour before sleep
?? Don’t sleep near your phones to avoid the risk of insomnia.