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The sun is the
main source of energy for all living beings, and an influence on mood and
well-being. However,
sun tanning has not always had a positive value in history: in
ancient Rome, in the 8th century up to the beginning of the 9th century,
to be tanned was synonymous with poverty and humble work. When well-being became linked to the
ritual of vacation, a lovely tan became associated with healthiness, care
and fashion.
In the past decades, also because of important climate
change, the sun's action has changed and we often tend to underestimate
its risks.
The campaign "Our
Friend the Sun" promoted by the Istituto Cavazza in collaboration with
community pharmacies AFM, Ascom, Sindacato Ottici, Istituto di Ottica
Benigno Zaccagnini, took place in Bologna in the month of June to create
awareness among the population on the importance of protecting ourselves
against ultraviolet rays.
At
a stand organized in Bologna's Piazza Maggiore, health professionals distributed
information flyers and gave advice to citizens. With the
help of special equipment,
passersby received a free examination of their sunglasses to verify their
suitability.
There was also analysis of
people's
skin phototype in order to obtain more information about the right choice of
sunscreen that should be used.
But why are sun rays harmful?
The
light that reaches the earth is composed of particles of variable energy
called photons which have various wave lengths (the
unit measure is the nanometer). The shorter is the wave, the higher is the energy
and, consequently, greater
is the penetration strength and higher is the risk of lesions.
The most
damaging rays are the UVC, which are almost all stopped by the ozone layer
around the earth, the UVB and the UVA. In the visible component of the
light spectrum, which interacts with our eyes' photoreceptors and allow us
to see, let us not underestimate the presence of the violet-blue rays
which, in values between 380 and 480 nanometers, can result in damaging
action and eye problems. |
Beyond the 700
nanometers, there are also infrared rays invisible to the eye but
perceptible because of the heat they provide. These rays in moderate
quantities do not represent risks.
The subject of sun protection is current even in winter,
though the radiation dose varies according to the location we are
in,
as well as the altitude, longitude and the time of day
we are out. UV rays increase by 4% in intervals of height of 300 meters
and the snow reflects up to 80% of the UV rays.
Clouds filter only 10% of ultraviolet rays, and that is what reaches us
when we stay in the shade, but since it is not
possible to stay in the shade during the skiing season, we need to protect
our eyes from the damaging effects of the sun.
There are in stores many different types of glasses; each
has their own characteristics relative to the lens and frame. How to
choose the right sunglasses?
It is
important to know that there are four categories of protection:
Category 0 -
1 (transparent filter,
very clear): for closed spaces and days with little
light.
Category 2 (medium filter): for medium light
and cloudy days.
Category 3 (dark
filter): for general use in full sun.
Category 4 (very dark filter): for strong lights, in the
mountains, for reflecting surfaces, not adequate for guiding.
To choose the best colour for your lens,
it is best to ask the advice of an eye specialist because some coloration
can produce variations on light, contrast and colour perception.
In conclusion, we have to choose our
glasses
based on the use we have for them, and we must remember to make sure that
the indispensable
quality warranties, the CE marking and the information flyer, are
provided. |