Standards and Directives

Standards and Directives

Various groups of people, including employees working for public authorities, in the business sector, in industry and in science and research as well as the general public comply with the standards issued by the DIN German Institute for Standardization. The DIN authorities play a major role in the compilation and publication of standards within CEN and ISO.

1. Standards

Standards - A Must for Ophthalmic Products

The DIN German Institute for Standardization (DIN), the European Committee for Standardization (CEN) and the International Organization for Standardization (ISO) are responsible for establishing fundamental technical standards and for stipulating the procedures and terminology used in optometry.
These institutions specify and constantly update the parameters which are essential for quality and uniform international standards.

2. EU Directives

EU Directives

EU Directives and National Legislation

The European Union
Within the European Union, merchandise must be able to move without obstruction and it must meet basic requirements with regard to its safety, suitability and performance. To achieve this goal, directives are compiled which must be implemented in the national legislation of the individual member states.

Standards for Optometry
The following standards apply for the field of optometry:
DIN 5361 for eyeglass frames,
DIN EN ISO 14889 for basic requirements to be met by eyeglass lenses,
DIN EN ISO 8980/1-3 for the requirements to be met by special lens types,
DIN EN ISO 13666 for ophthalmic terminology,
and the directives 89/686/EEC for sunglass lenses and 98/42/EEC for medical devices.

The latter contains equirements which must be met by eyeglass lenses, eyeglass frames, contact lenses and ophthalmic instruments.

Learn more

3. The CE Marking

CE Marking

Labeling Requirements
Since June 14, 1998, the CE (CE = Communité Européen [European Community]) labeling requirements have been in force for products to which EU directives and the relevant standards apply.
The CE marking is the consumer’s guarantee that the minimum safety and performance requirements are met by the product to the extent stipulated by standards.

The CE Marking
The CE marking is applied to a clearly visible area of the product by the manufacturer, provided it would not impair the function of the product, as is the case with eyeglass lenses. In such cases, the packaging and instructions for use are labeled accordingly.

Learn more

4. ZEISS Quality

ZEISS Quality

Six criteria that make ZEISS quality so special

The ZEISS guarantee certificate you receive from your eye care professional with your new eyeglass lenses verifies that you have purchased a high-quality product.

It contains, for example, the 6 criteria which are distinctive characteristics of ZEISS quality:

  1. Carl Zeiss is certified to DIN EN ISO 9001/2000. This certification goes far beyond the minimum legal requirements of the CE mark and includes stringent requirements to be met not only by the product itself, but also by the staff processing it.
  2. We guarantee that the optical quality of our lenses takes precedence over all other product criteria.
  3. The internal test specifications of ZEISS exceed the requirements of the relevant standards.
  4. ZEISS can also provide you with lenses in very high or unusual prescriptions. And our many different coatings are also available for these powers.
  5. You can be sure that ZEISS lenses will continue to be available in the long term, ensuring that you also receive optimal lenses of proven quality in the future.
  6. We ensure that ZEISS lenses are fitted exclusively by selected eye care professionals.
Softly does it!

Softly does it!

The best way to clean your lenses is to hold them under cold, running water using pH-neutral cleaning agents. Dirt particles are simply washed off and therefore cannot cause any damage to the surface when the lenses are dried with a clean, soft cloth. For cleaning your lenses when you are out and about, we recommend the microfiber cloths and the special ZEISS lens cleaning agent. Other textiles may cause scratches on your lenses.
Important: Please do not expose your lenses to high temperatures of over 80 °C (e. g. in the sauna or on the dashboard of your car in the summer).

Learn more

5. DIN EN ISO 14889 and DIN EN ISO 8980-3

DIN EN ISO 14889

Basic Requirements
This standard, which was compiled with the participation of international experts, specifies the basic requirements to be met by finished, uncut eyeglass lenses. These requirements cover subjects such as physiological compatibility, flammability, testing for mechanical strength and the transmittance of uncut, finished eyeglass lenses.

Requirements to be met by lenses used for driving
Transmittance, and particularly the transmittance requirements that must be met by lenses used by drivers, is of great importance not only for Carl Zeiss as a lens manufacturer, but also for eye care professionals.
If, for cosmetic or medical reasons, patients wish to purchase lenses which are not suitable for use in traffic or for night driving, the eye care professional is obliged to inform them accordingly. He or she should stress that it is not only the intensity of the tint that influences the suitability of a lens for use in traffic, but also the ability of a lens to transmit certain wavelengths. For instance, a lens with a certain filter effect may subjectively appear to be "bright" enough for diving in twilight or at night, but it may falsify the color of a traffic signal to such an extent that it is not suitable for driving.

Learn more

6. Lenses used for Driving

Lenses used for driving

Transmission curves for F 451 and F 452. These special filter lenses meet the additional requirements, (τ 475-650, Q red, Q yellow) which must be met by lenses for use in traffic.

Additional requirements to be met by lenses used for driving

  • Lenses used for driving in the daytime must display a luminous transmittance τν of > 8% in the major reference point using standard illuminant D 65.
  • Lenses used for driving in twilight or at night must display a luminous transmittance τν of ≥75% in the major reference point using standard illuminant D 65.
  • The spectral transmittance τ (λ) of the lens must not be less than 0.2 times the luminous transmittance τν for any wavelength in the range from 475 to 650 nm.
  • The relative visual attenuation quotient Q must not be less than 0.8 for red, yellow and 0.6 for green, and 0.4 for blue.

Needless to say, all lenses supplied by ZEISS are tested and labelled in accordance with the specifications of these standards (suitability for use in traffic / suitability for twilight or night driving as per DIN EN ISO 8980-3).

All ZEISS lenses also meet the minimum requirements concerning mechanical strength, inflammability and physiological compatibility.

Principles for Transmission Requirements for Lenses

Relative spectral radiance of standard illuminant D 65 depending on wavelength

Principles for Transmittance Requirements for Lenses

  • Luminous Transmittance τν
    Luminous transmittance τν is the ratio of the luminous flux transmitted by the lens to the incident luminous flux, taking into account the spectral luminous efficiency of the eye in daylight V(λ).
  • Spectral Transmittance τ(λ)
    The spectral transmittance τ(λ) is the ratio of the spectral radiant flux transmitted by the lens to the incident radiant flux at any specified wavelength λ.
  • Standard Illumnant D 65
    The standard illuminant D 65 represents medium daylight conditions with the color temperature 6500 K and is usually generated by the use of xenon lamps with filters.
  • Attenuation Quotient Q
    The relative visual attenuation quotient Q is the ratio of the luminous transmittance of a tinted lens for the spectral radiant power distribution of the light emitted by a traffic signal tsign to the luminous transmittance of the same lens for the standard illuminant D 65. Q therefore does not provide any information on the wearer’s color perception with a lens, but only indicates whether the luminance of a traffic light is more or less strongly attenuated than the ambient luminance (Q less or greater than 1).
  • Spectral Luminous Efficiency of the Eye in Daylight τ(λ)
    The spectral luminous efficiency of the eye in daylight τ(λ) is the defined relative spectral sensitivity of the light-adapted photopic standard eye whose maximum is referred to λ = 555 nm in air.
Learn more

7. Other Standards

Other Standards

Other Standards relevant to ophthalmic optics

Apart from DIN EN ISO 14889 and 8980-3, there are other standards which are also essential for ophthalmic opticians and optometrists which go into more detail with regard to the various types of ophthalmic lenses and their mounring:

  • DIN EN ISO 8980-1 Requirements for single vision and multifocal lenses
  • DIN EN ISO 8980-2 Requirements for progressive lenses
  • DIN EN ISO 13666 Ophthalmic terms and definitions
  • DIN EN ISO 21987 Ophthalmic optics - Mounred spectacle lenses