Work looking through your eyes

Special eyepieces

They have additional properties that can facilitate vision and increase user well-being.

Other, of circular cross-section
These glasses reversibly modify their transmission factor in the visible under the influence of solar radiation intensity, temperature and other parameters. This change is not instantaneous but varies with temperature and material. If used while driving, it should be noted that the windshield filters UV radiation from the sun, preventing darkening of most sunglasses of this type.

Polarized sunglasses
Sunlight is not polarized; when reflected on some bright horizontal surfaces (water, snow, road, slate quarries, etc.), it is polarized in a single plane, usually horizontal; the use of polarized sunglasses allows to eliminate this parasitic polarized light (reflections) avoiding glare. The screens of most electronic devices (tablets, smartphones, etc.) incorporate polarized screens whose vision becomes difficult if the user wears glasses with polarized sunglasses.

Degraded sunglasses
In these eyeglasses, the hue gradually clearens; the upper part is darker and the lower part lighter.
They are best suited to wear indoors and in low sunlight; however, it should be borne in mind that the more degraded bottom is easier for reflections from bright horizontal surfaces to penetrate.

Aspects to consider

• All sunglasses must be accompanied, among other things, by the following information: » Visible, legible and indelible CE marking. » Model identification. » Manufacturer identification. » Reference to the standard against which the equipment has been certified. » Eyepiece protection class or, where applicable, its category. » Use restrictions.

• The manufacturer must provide with each PPE the instructions for use, maintenance and periodic review written in the official language of the destination country.

• The selection of PPE for sun protection requires knowledge of the workplace and should be reflected in the risk assessment.

• The protective effectiveness of PPE protecting the eye from solar radiation will be optimal if the worker uses it in accordance with the manufacturer's instructions.

• Particular attention should be paid in the selection of sunglasses to the limitations of their use depending on their class or category of protection, e.g. unsuitable for driving and road use or unsuitable for driving at night or in twilight or low light conditions.

• The color of sunglasses is not a determining factor; the darkest is not always the most protective. The transmission of solar radiation in VIS depends on color, but it is the material that determines the spectral transmission coefficient in UV.

• The shape and size of the eyelid is often a matter of fashion. However, in some circumstances, it is appropriate to choose sunglasses that are wraparound or with side protection.

• In certain cases, such as prolonged exposure to the sun in desert environments, it may be necessary to wear sunglasses with specific IR protection requirement (protection code 6 in work sunglasses or with IR radiation protection in general use sunglasses).

• Some eyepieces may have an anti-reflection treatment that eliminates or reduces reflections that can sometimes be bothersome.

• In extreme lighting conditions, especially in snowy areas, the risk of exposure to the VIS blue part of the solar spectrum should be considered. It should be stressed that direct sun vision is dangerous due to its high blue light content (specifications for eyeglasses for direct sun observation are contained in UNE-EN ISO 12312-2).

Exposure to solar radiation

While RD 486/20101 on occupational exposure to artificial optical radiation excludes solar radiation from its scope Law 31/1995 establishes that the safety and health of workers must be guaranteed in any aspect related to work, which includes, among others, the risks derived from solar radiation. Farmers, construction workers, seafarers, gardeners, and rescue workers are some of the professions most exposed to this radiation.

In the workplace, in the face of a potential risk from exposure to solar radiation, an action plan should be put in place which may require, among many other measures, the use of specific Personal Protective Equipment (PPE) such as sunglasses.

Filtering eyepieces against solar radiation

Sunscreen glasses (hereinafter referred to as sunglasses) are equipped with eyepieces that filter against this radiation. The main purpose of filtering eyepieces against solar radiation (solar eyepieces, in the following) is to protect the human eye from the harmful effects of excessive solar radiation this may lead to pathologies such as photokeratitis, photoconjunctivitis, cat aratas or photoretinitis. Similarly, wearing sunglasses, from an ergonomic point of view, increases user comfort and visual perception.

The choice of sunglasses depends on the level of ambient lighting and the individual's sensitivity to glare, in order to ensure fatigue-free vision even in the case of prolonged use.

• General purpose sunglasses

Such equipment usually meets the requirements of UNE-EN ISO 12312-12, which specifies the mechanical, optical, etc. properties of sunglasses intended for general use, which only offer protection against solar radiation. This standard classifies sunglasses according to their transmission factor in the visible spectrum in categories from 0 to 4.

• Working sunglasses

This equipment is normally certified according to UNE-EN 166 which states that sunglasses must be marked with the class of protection (represents their transmission properties) which is a combination of 2 numbers, where the first refers to the type of radiation from which it protects (protection code) and the second indicates the degree of protection of the eyepiece (higher degree of protection, greater absorption of incident radiation and, in general, less transmission in the visible).

Protection class = protection code + protection degree

1.1 to 4.1 = Degree of protection
5 = No specification in the IR
6 = With specification in the IR

In a complementary and specific manner, the UNE - EN 172 standard defines the protection classes and the transmission coefficient requirements corresponding to solar eyepieces for work use, with the rest of the requirements for this type of eyepieces contained in the UNE - EN standard. 166. In this case, sunglasses, in addition to protection against solar radiation, offer protection against other additional risks such as impacts, splashes, etc.

Both general purpose and professional sunglasses fall within the scope of Regulation (EU) 2016/425 laying down the conditions for the placing on the market and free movement of PPE and, in accordance with Annex I thereto, both types are considered as PPE.

Like any other PPE, sunglasses must carry the CE marking, which indicates that they comply with the essential health and safety requirements set out in the Regulation.

Requirements for protection against solar radiation

In general, solar eyepieces must ensure, in addition to a certain absorption of visible radiation (VIS), eye protection in the ultraviolet (UV) spectral region and, in some cases, in the infrared (IR); There are no significant differences in the specifications and requirements in this regard between sunglasses for work use and those for general use, and it is possible to establish a certain correlation between them.

References

• Solar radiation protection glasses triptych (Download PDF)

• EN ISO 12312-1:2013 Protection of the eyes and face. Sunglasses and associated equipment. Part 1: Sunglasses for general use.

• UNE-EN ISO 12312-1:2013/A1:2015 Eye and face protection. Sunglasses and related items. Part 1: Sunglasses for general use.

• UNE-EN ISO 12312-2:2015 Eye and face protection. Sunglasses and associated equipment. Part 2: Filters for direct observation of the sun.

• UNE-EN 166:2002. Individual eye protection. Specifications. • UNE-EN 167:2002. Individual eye protection. Optical test methods.

• UNE-EN 168:2002. Individual eye protection. Non-optical test methods.

• UNE-EN 172:1995. Individual eye protection. Sun protection filters for work use.

• UNE-EN 172/A2:2002. Individual eye protection. Sun protection filters for work use.

• Eye and face protection. Selection and use sheets. INSST.

• Technical guide for the evaluation and prevention of risks related to artificial optical radiation. INSST.

• Technical guide for the evaluation and prevention of risks for the use by workers of personal protective equipment at work. INSST.

• Royal Decree 773/1997, of May 30, on minimum health and safety provisions relating to the use of personal protective equipment by workers.

• Law 31/1995, of November 8, on Occupational Risk Prevention.

• Regulation (EU) 2016/425 of the European Parliament and of the Council of March 9, 2016 regarding personal protective equipment and repealing Council Directive 89/686/EEC.