Light is a type of energy in the form of electromagnetic radiation of a wavelength. Natural light comes from stars and the sun, whereas artificial light uses some form of energy, i.e., electricity, solar or gas and comes is in the form of lamps, fluorescent lamps, LED (light emitting diode) lights.
Both natural and artificial lights are visible forms of light which can be detected by the human eye.
The range of light we can see is called the visible light spectrum, which is made up of the 7 main colours of the rainbow positioned according to their wavelength and energy, i.e., red having the longest wavelength and least energy, followed by orange, yellow, green, blue, indigo and violet having the shortest wavelength and most energy.
Apart from promoting the production of vitamin D in the body, prolonged exposure to the sun’s UV (ultraviolet) light rays can be damaging to the skin and eyes. It is important for people exposed to strong sunlight to wear proper protective attire, as even short-term exposure to strong sunlight can damage human eyes, skin, and cause visual damage. Hence the advice to always wear proper eyewear that block UV light rays, sunblock and clothing when going outdoors.
Looking directly at the sun can cause permanent damage to a person’s vision!
Here are some interesting facts on the effects red light and blue light have on human eyes.
Having the least energy, red light is used as visual therapy for eye health and protection against vision loss.
Red light therapy is used to stimulate the ocular cells in the eyes to work efficiently. This therapy is mainly used to help people suffering from age-related macular degeneration.
Another eye disease, retinitis pigmentosa, is a common inherited cause that leads to blindness. The retinal cells break down and cause a loss of peripheral vision, night blindness, and eventually total vision loss. Here again, red light therapy has been found to help stimulate the ocular cells and prevents photoreceptor cell death, thus it preserves retinal functions.
Red light therapy is also used effectively in glaucoma treatment, optic nerve injuries by speeding up the recovery of eye functions, and also reduces inflammation.
People know how UV light can damage their eyes, but are unaware that blue light is also damaging their vision on a daily basis as blue light has a lot of energy. Exposure to adequate blue light helps stabilize our circadian (body) rhythm; however, exposure to too much blue light disrupts it and causes other body function problems.
Those who work long hours on electronic devices should be aware that blue light is a “silent killer” to their vision, as blue light causes Digital Eye Strain better known as Computer Vision Syndrome. Over time, this can lead to macular degeneration which may end up in visual impairment, as blue light can pass through all the way to the back of the eye.
Certain lenses can block blue-violet light, so the use of special computer glasses with yellow tinted lenses may provide comfort to users on electronic media for long periods of time.
Green and yellow lights:
Green light also helps regulate the circadian rhythm, although overexposure to it and blue light at night can reset your biological clock.
Yellow light is effective to protect eyes exposed to excessive blue light, and yellow lenses filter out UV and blue light as well.
A person should consult a qualified ophthalmologist to discuss ways to prevent overexposure to UV light, and the ophthalmologist will prescribe the best solution. It may be a pair of UV protection sunglasses or special prescription lenses.
The same goes for protection against blue light, where the ophthalmologist may prescribe blue light glasses or computer glasses with yellow tinted lenses, depending on the condition of your eyesight.
This is a general summary of the effect of different types of lights on your eyes, which we hope is informative. This article is in no way to be taken as medical advice and readers should refer to a qualified ophthalmologist for proper advice.
2nd July 19:40