Technology advances daily by giant steps, our life has been filled with LCD screens, we spend approximately 30% of our time in front of the computer or laptop, the smartphone and even the television, but we do not take into account how this affects our visual health. Although they may seem harmless, the LED backlight modules that LCD screens have, emit a large amount of blue light, named for the cold hue it radiates. Blue light is part of the electromagnetic spectrum that the human eye perceives, it is emitted both by natural sources such as the sun and by artificial sources, especially by electronic devices.
Regarding its wavelength, blue light is found below 400 nm (ultraviolet zone) and above 750 nm (infrared zone). This is why being exposed to it for a long time becomes dangerous for our eyes, because it can damage the photoreceptors and cells of the retina. Some of the problems caused by prolonged exposure to blue light are:
Computer Visual Syndrome (SVI):
- Red eyes
- Eye fatigue
- Eye dryness
- Decreased frequency of blinking
- Alteration of circadian rhythms
Due to its short wavelength and high energy, blue light partially suppresses the synthesis of melatonin, which is the sleep hormone, causing insomnia as a consequence. Being exposed to blue light without protection is dangerous for visual health, its effects are cumulative and chronic, and even cause complicated photochemical damage.
How to protect ourselves from blue light
To protect our eyes from receiving a large amount of blue light, specialists have designed glasses with specific filters that reduce the excess of this type of light by lowering its intensity between 15 and 20%, thus helping to protect our vision. Many have wondered if these new filters really protect our vision or are just a way to sell the use of glasses, that is why various specialists have been developing studies on this. In 2018, an optical chemistry investigation showed that being exposed to blue light without protection can generate macular degeneration, this is a degenerative and irreversible disease that causes loss of vision.
Based on the investigation, glasses that filter both UV rays and blue light can be used, whether they come from a natural or artificial source. In the same way, other studies on blue light and the damage it causes show that there are populations with a higher risk of developing visual conditions due to overexposure. That is why they recommend wearing glasses with special filters, especially to those who suffer from dry eye syndrome as well as to users who usually use contact lenses.
Based on the results of these studies, the manufacturers of filters or solar lenses claim that blue light glasses can relieve eye fatigue, improve the quality of sleep. In addition, these can also provide retinal protection against phototoxicity, especially with regard to the protection of the macula, which is why both optometrists and ophthalmologists recommend their use.
Types of blue light filters.
To protect yourself from exposure to blue light, you can find two types of filters depending on the color of the lens, the most common is the yellow-orange tone used in sunglasses, this absorbs blue light and helps reduce visual fatigue.
However, transparent lenses have also been developed with filters that filter part of the blue light we receive, these are only to be used when we are in front of the screen.
The 3 types of blue filters are:
– Internal blue filters these apply only to the lens mass and filter approximately 20% of blue light. These have the advantage that they do not produce reflections.
– External blue filters these are found on the surface of the lens, this type of filter alone can filter up to 20% more or less.
– Combined blue filters, this type combines both filters, a filter on the mass and another on the surface, these glasses filter blue light approximately 30%, and it is usually recommended for those people who for work reasons must spend a lot of time in front of their computer or laptop.
Other methods to protect our vision from blue light
Although we can use the lenses with solar filter when we are in front of led screens, we must be aware of not overexposing ourselves to this light, that is why we must take a series of measures for prevention: Reduce the hours you spend in front of the screens of your devices, although we know that using them may be necessary for our work, it is important that we also take care of our vision.