A closer look
23 September 2019
When making decisions about eye protection, you need to take a close look at the working environment. Matteo Baroni explores the risks and the options.
WORKING ENVIRONMENTS are not all the same, that’s why the law identifies the risks that affect the various situations.
Users have to be protected from 3 risk categories
Category I only includes minimum risks :
a) superficial mechanical injuries;
b) contact with moderately aggressive cleaning products or prolonged contact with water;
c) contact with hot surfaces (within 50°C)
d) ocular injuries caused by exposure to sun rays (different from injuries caused by sun observation)
e) non extreme atmospheric conditions
Category III includes “only the risks that can cause very serious consequences as death or irreversible health damages due to”:
a) substances and mixtures which are hazardous to health;
b) low oxygen atmosphere
c) harmful biological agents
d) ionizing radiations;
e) high temperature environments with effects comparable to an air temperature of at least 100° C
f) low temperature environments with effects comparable to an air temperature of -50°C or lower;
g) high altitude falls;
h) electric shock
j) hazards associated with chainsaws
k) high pressure jets
l) injuries caused by bullets or knives;
m) harmful noise
Category II “includes the risks that are not listed in categories I and III”
Ocular protection must meet various criteria and grant to the PPE and adequate degree of comfort. For this reason, companies are continuously looking for new technologies to make the PPE always more safe and functional.
Today, thanks to the high optic and mechanical properties the most employed material for eye protection is monolithic polycarbonate. It presents the highest resistance among transparent polymers: it deforms during impact but it does not disperse in small fragments harmful for the eye, it dissipates into the air, it is weatherproof, highly resistant to chemical agents and detergents, highly workable and easy to clean and heat resistant.
A good material is not enough to reduce the effects that diminish visibility and therefore increase the risk of injuries. Very often, we cannot see or we do not know that some characteristics make the glasses highly performing, sometimes it is a special coating that significantly changes the optical properties of the lenses, sometimes it is the frame that makes the glasses more comfortable.
One of the coatings that can change the vision is anti-reflection. Artificial light and reflecting surfaces create visual glare that can lead to reduction of the attention span, limited vision and, in extreme cases, dizziness. The anti-reflection treatment consists in a layer of metal oxides able to eliminate residual light reflections that have negative effects on the clearness of the images perceived. It is an active protection as it prevents the risk of injuries by eliminating the glare and improving visual acuity/quality.
This filter is essential in working environments as: nightly road works, logistic warehouses and glass processing.
In high humidity or high steam environments and during intense working activities, the lenses could fog up creating a condition of reduced visibility and potential danger. In these situations, it is fundamental to use glasses or masks with anti-fog treatment.
Another essential treatment for protection glasses is the anti-scratch treatment that grants resistance toabrasions and therefore a longer life.
In some environments drops and sudden water and oil splashes could expose the worker to a sudden reduction of the visual field caused by the presence of these liquids on the lens surface that create halos and poor visibility. In these cases, the hydrophobic treatment eliminates the hazards making the lens totally smooth and waterproof, avoiding the accumulation of liquids on the surface and granting a clear vision.
There are special treatments that allow high visibility in any lighting condition.
During daytime, changing from a bright to a dark environment and vice versa causes the abrupt closing or opening of the pupil sharply reducing visual acuity. This physiological phenomenon presents different reaction times from person to person, in any case exposing the worker to the risk of a temporary loss of visibility. The use of glasses with In/Out lenses by reducing the activity of the pupil cancels the risk allowing a high visibility in any light condition. This lens is submitted to a reflective multilayer treatment on the external surface in order to filter ambient light.
The prolonged use of notebooks, led monitors, tablets and smartphones reduces blinking up to five times. This can cause eye fatigue and headaches associated to blurred vision, eye soreness, double vision and sensitivity to light.
These harmful effects can increase with the use of electronic devices in the evening hours. In fact, the exposure to blue light influences the circadian rhythm, responsible for a good sleep/wake cycle, causing sleeping disorders.
The use of glasses with specially treated lenses is a valuable factor that can be adopted both in case of prescription glasses and with no visual defects.
The anti-blue light treatment allows reducing the action of blue rays, improving contrast and visualcomfort and reducing glaring and reflex on the lens.
Not only the treatments on the lens can improve the visual condition, but also the filter is fundamental for the choice of the correct PPE according to the various environments.
In outdoor working condition, it is fundamental to choose the right lens that can grant optimal visibility in safe conditions.
There are solar lenses that can filter up to 85% of solar light; this means a reduced visual fatigue and an optimal and comfortable protection that can supply a perfect visibility also in case of reverberation.
In presence of reflective surfaces, the light beams reverberate in all directions; only polarized lenses block the reflex, as the common sun lenses are not sufficient even if they filter UV rays.
What polarized lenses mean?
In order to answer this question it is necessary to briefly describe how polarization works.
Natural light travels in W waves that swing in any direction. This means that it is not polarized.
When a sunray hits a reflective surface, the light goes under a process that is called polarization and starts to move vertically and horizontally.
While vertical light supplies all the useful information on colors and contrasts, horizontal light creates an annoying glare effect that disturbs the vision.
The polarized filter thanks to a vertical micro network sensibly reduces or eliminates the reflected luminous energy, responsible for the glare effect.
Photochromic lenses are ideal for protection glasses both in and outdoor, they darken as a reaction to UV light in less than 1 minute and they gradually become clearer in absence of ultraviolet light in about 5 minutes. Photochromic lenses are recommended for in & outdoor activities with a permanence in- or outside higher that the reaction times of the lenses, such as in absence of abrupt light changes.
“Photochromic” is not the definition of a treatment to the lens, it is a molecule that activates or darkens the lens when exposed to UV sunrays.
There have been major improvements not only in the treatment of lenses but also in the development of technologies studies to optimize ergonomics, granting an higher comfort level when wearing protection glasses.
The various regulations of the temple and the nose bridge improve the adaptability of the product and the characteristics of the user’s countenance, but this is not enough. The study of new materials, especially rubber, allows a perfect adherence in various conditions.
New technologies allow a complete adaptability. The temple support area provides a stable and comfortable wear. The various systems present an excellent adaptability thanks to the regulations of the inclination and length of the temple that in the major part of the cases presents a terminal part covered with rubber with a tilting movement that allows the glasses to lean on the temple with perfect adherence.
An adjustable nasal bridge regulates the height of the glasses in order to allow vision through the central part of the lens where the maximum optical quality is granted.
Some glasses are engineered for a perfect combination with other PPE. An example are ultra-thin temples that allow an optimal interaction with earmuffs, allowing the maximum performance in terms of sound attenuation.
These are only a few technologies that make the protection glasses comfortable so that always more people start wearing them and caring for their eyes.
Matteo Baroni is marketing manager at Univet. For more information, visit www.univet.it/en/