Sunlight is vital to life on our planet. However, excessive and inappropriate exposure to sunlight can cause damage to our sight and health in general.
The harmful effects of the sun result from direct exposure to ultraviolet light, also known as UV rays.
In the natural world, between 80% and 90% of UV rays pass through clouds and approximately 60% of the total radiation is received between 10 a.m. and 2 p.m.
UV rays generated by sunlight energy are dangerous for our eyes, as well as for our skin.
Electromagnetic radiation emitted by the sun can be divided into two categories: ionizing radiation (ultraviolet radiation such as UVA, UVB and UVC; X rays and gamma rays), which can alter the external environment; non-ionizing radiation (visible spectrum radiation, infrared light, radio waves and microwave radiation), which has significantly lower energy levels and therefore can interact with the environment only on a surface level.
We can distinguish, in turn, three types of UV rays:
● UVA: This is the sunlight radiation that reaches our planet the most. UVA rays are the main cause of skin melanogenesis and are responsible for what we call tanning. This is why using sunscreen with a high sun protection factor (SPF) is important when we expose ourselves directly to sunlight;
● UVB: Sunlight radiation that can be potentially harmful if absorbed without any precaution. The majority of UVB rays are filtered by the atmosphere and clouds, but can still cause damage such as skin aging, skin cancer, cataract, actinic keratoconjunctivitis, retinal damage and skin burns of various degrees;
● UVC: These are the most intense and dangerous rays of all and are totally blocked by the earth’s atmosphere thanks to the ozone layer. Since UVC rays can kill any virus, mould or bacteria, they are often used in UV light sterilization technology (UVC lamps).
Our eyes constantly interact with electromagnetic radiation, which allows us to explore and engage with the environment.
However, exposing oneself to sunlight without precaution can cause damage to the eyelids, cornea and retina.
The most effective protection measure for our eyes is wearing sunglasses, since they are an indispensable protective barrier. Rather than being a mere habit, wearing sunglasses fitted with protective lenses can be a practical way to defend our eyes from potential damage. In particular, wearing sunglasses is recommended during the hours when UV radiation is at its most intense, between 10 a.m. and 2 p.m.