How dangerous is the blue light from the screens we use for our eye health?;
Exposure to certain wavelengths of blue light are associated with Age-related Macular Degeneration (AMD) and even carry risks of possible blindness!
The retina is a light-sensitive neurine inner lining of the eye, in which the image of the image we see is reflected.
The macula is the central area of the retina and contains nerve photoreceptor cells (photoreceptors), which convert visual information into an electrical signal in order for the brain to process the image. The macular region is particularly important for our central and colour vision, but also for carrying out important daily activities such as recognising objects and faces.
Age-related macular degeneration (AMD) is a condition that affects people over the age of 50 and involves the degeneration of the retinal nerve cells. This condition has affected more than 50,000 people in our country, while globally, 150 million people have been diagnosed with the disease. According to studies, this figure is expected to increase in the coming years.
In most cases, IOP is caused by atrophy of the retina, due to damage to the melanocytic epithelium cells (cells that contain the pigment melanin and bind light that is not absorbed by the photoreceptors, thus protecting the eye from ultraviolet radiation).
EEE is divided into dry and wet type. In dry-type EIA, there is a gradual destruction of the photoreceptors, resulting in a gradual loss of central vision. Wet EIA is accompanied by the appearance of new abnormal vessels, which are extremely fragile and may rupture and bleed. This condition leads to the collection of blood, fluid, lipids and even detachment of layers of the eye, resulting in blindness.
The risk factors associated with the disease are age (over 50 years), smoking, genetic factors and a poor antioxidant diet. Recent studies suggest that exposure to blue light is a potential risk factor for EAD.
What is the relationship between blue light and our eyes and how is it related to the EEG?;
A few words about the blue light..
Blue light is part of the visible spectrum, specifically 415-495nm. Blue light is divided into 2 parts: a) The blue-violet (415-455nm) and the blue-turquoise (465-495nm). When light in the blue-violet spectrum «hits» the eye, a unique process takes place. As the light-sensitive nerve cells in the retina begin the process of phototransformation to convert visual information into a nerve signal, our eye produces some intermediates that allow even more blue-violet photons (small packets of energy) to enter than any other light in the optical spectrum. This exposure causes changes in the function of the cells of the eye, producing reactive oxygen species that disrupt the structures and functions of the membranes of the retinal nerve cells, such as the retinal epithelium. The result is the accumulation of waste-products (lipofuscin) in the retinal cells.
It should be stressed that not all blue light is harmful. In fact, the two bands mentioned above (blue-violet and blue-turquoise) have very different effects on the eyes. In addition to its contribution to visual acuity, contrast sensitivity and colour vision, light in the blue-turquoise spectrum is necessary for the reflex of reducing the diameter of our pupil in bright light, and for the synchronisation of our circadian rhythm (the rhythm that constitutes our internal clock and relates to the biological processes that occur in our body over a 24-hour period). Exposure to blue-turquoise light also helps us to regulate our memory, our mood, achieve hormonal balance and maintain our general health. On the other hand, exposure to blue-violet light is harmful to the retina and over time causes gradual cell death of the tissue.
What is the relationship between exposure to light and EEEO?;
Epidemiological studies correlate chronic exposure to sunlight with EEG. In particular, a study from the Beaver Dam Eye Clinic in the USA showed that sunlight exposure in adolescents and young adults is strongly associated with a high risk of developing abnormalities in the structure of the melanocytic epithelium and incipient EEG. Also, in a Chesapeake Bay Waterman study, a group of participants with advanced stage EEG reported high levels of blue light exposure over the previous 20 years. More recently, a European study (EUREYE) reported a significant association between long-term blue light exposure in participants who consumed products low in antioxidants (including vitamin C, E, zeaxanthin and iron).
In general, the amount of exposure to blue light varies depending on the time of day, location and season. During the daytime, 25-30% of sunlight consists of blue light, which may also be present in modern light sources (LEDs), small fluorescent lamps, and high energy efficiency luminaires. The cooler the light, the more blue light it emits. Other sources of harmful blue light include electronic devices , such as televisions, laptops, smartphones and tablets. The popularity and necessity of such devices ensures our constant exposure to high-intensity blue light.
Unfortunately, this accumulative effect over time can cause damage and later destruction of retinal cells, leading to EEG. For this reason, we stress that protecting our eyes from exposure to harmful blue radiation is of utmost importance.
What are the protection measures against blue light exposure?;
The consumption of dietary supplements rich in antioxidants and zinc (which are also given to patients already suffering from HEA) is extremely beneficial, as they appear to reduce the risk of developing HEA by 25%. High dose combination of vitamins C, E, beta-carotene and zinc have also been suggested to reduce retinal damage from excessive blue light exposure. Equally important, however, is limiting patients' exposure to electronic devices, as well as expert advice to protect against ultraviolet radiation caused by blue-violet light.
Tips for protection from ultraviolet light of electronic devices
Nowadays there are technologies in eye lenses that reduce the levels of exposure to harmful radiation in the blue-violet spectrum, while allowing the rest of the visible spectrum to enter the eye. There are many eye lens companies in the country that provide so-called «blue-blocking» filters. Also, some intraocular lens manufacturers (which replace the crystalline lens of the eye in the case of cataracts) include «blue-blocking» pigments in certain lenses, including UV-blocking, for ultraviolet radiation.
Daily exposure to the blue light that comes from modern lighting and electronic devices should be compared to the exposure to ultraviolet (UV) radiation that we have known for decades in order to understand the seriousness of the situation.
Proper eye protection in adolescence and early adulthood could go a long way towards reducing the risk of developing IOP and irreversible blindness in older age. Education of patients to this end and the advice we as experts should give on the risks and protection from harmful blue light sources is essential, despite the fact that electronic devices are an integral part of our daily lives.
