Opthalmic lenses

Classification of spectacle lenses from the perspective of vision:

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Single-vision or monofocal lenses

In single-vision lenses, there is only one strength, which is designed for viewing distant or near objects or the computer screen

Prices from 32 €/per pair. See the price list here.

Single-vision lenses include both “-” and “+” lenses. Minus lenses are usually worn all the time and are used for driving, watching TV, and in the theatre/cinema.
Young people can also successfully use them for reading or looking at the computer screen.
Plus lenses are used for reading from a distance of 35-50cm and/or looking at the computer screen according to the prescription. 



Minus lenses  

Approximately a half of those wearing glasses are shortsighted and require minus lenses for seeing.

The lenses are worn all the time. Such lenses are mostly prescribed when the wearer is a teenager or in the early 20s. There is no single reason for the formation of shortsightedness, genetics as well as the person’s environment play a part. A need for minus lenses does not go away if one avoids wearning glasses or by doing exercises for the eyes. Exercises are, however, beneficial for eye muscles and improve both the cooperation as well as the accommodation of the eye muscles.



Plus lenses  

In a younger age, most farsighted people are not prescribed glasses, because the accommodative ability of the eyes compensates for the required plus strength. Plus lenses are usually prescribed for young people in the case of very high strengths or for older people. 

Age-related reading glasses  

In general, most people will require reading glasses when they reach their 40s. 

There are also those who are no longer able to read from near distances with their minus lenses. The initial deficiency arises when viewing objects from 30-50 cm away. From the middle of the 50s, it is no longer comfortable to view the computer screen (50-70 cm) without spectacles or the viewer must remove the spectacles. Yet, the person still requires spectacles for viewing distant objects.

Multi-vision or multifocal lenses

Multi-vision lenses are primarily designed for the people over the age of 40, who require two different strengths of lenses for viewing distant and near objects. Prices from 55 €/per pair. See the price list here.

Multi-vision or multifocal lenses are divided into progressive and bifocal lenses. Progressive lenses allow the wearer to see all distances clearly by only moving their head smoothly to find a sharp area. On the top of the lenses, there are strengths for viewing distant objects, on the bottom, however, the strenthts for reading. In the middle of the lens, the strengths change smoothly from distant strengths to reading strengths, which allows to see the computer screen sharply as well. Progressive lenses certainly take a bit of time to get used to at first. The customer must always be explained how the lenses function during the vision check or at the time of purchasing the lenses, so the wearer will know what to expect from their new pair of glasses. Bifocal lenses are so-called inflexible lenses, which can only be used for seeing near and distant objects, the objects in the middle remain blurry. Thus, these lenses are rarely sold today.

More about progressive lenses:

Nova HD: Nova’s progressive lenses with the widest channel, which ensure natural, high-contrast vision to all distances. 20% wider range of vision compared to regular progressive lenses in reading or viewing medium distances. Very comfortable for viewing digital equipment and smooth transitions between different zones of vision. The parameters of fitting of the frame and a lifestyle questionnaire are taken into account for personalisation. 

Nova Tiny: Progressive lenses of aspherical design and digital surface finishing, which are suitable for very narrow frames, installation height from 13mm.
Wide range of vision for distant, medium and near distances. 

 

Nova 3Di: Progressive lenses, which are made with the help of a high-tech technology consisting of computer-controlled tracing of rays of light (ray-tracing) in order to create one of the most developed technologies in the market for manufacturing progressive lenses. 100% back surface design. Thanks to the free-form technology applied, it is possible to make lenses with almost distortion-free peripheral areas and the best quality of vision is ensured by                                 taking into account the individual paramaters of each wearer.

Nova Plus: Aspherical lenses with a designed back surface, which decreases distortions and expands the field of vision. The design of the lenses uses the abberation filter system and binocular balancing. Lenses of very good price and quality ratio. 

Traditional progressive: Regular soft-design progressive lenses with the areas of distant, near, and medium                                         vision of the width of the middle channel.

Ranges of vision with different progressive lenses:

         Nova HD                        Nova 3Di                     Nova Tiny                      Nova Plus             Trad.progressive

Lenses with an extended range of vision   

When single-vision reading glasses are not sufficient for seeing the computer screen (medium distance) clearly or when your reading glasses are in the way of seeing the computer screen or the near vicinity of your place of work clearly, it is possible to use lenses with an extended range of vision. 
Prices from 93,6 €/per pair. See the price list here.

Such lenses contain several different strengths. They ensure equally clear vision for reading as well as for using the computer, while also being able to observe the surroundings of the workplace. Depending on the user’s age and the prescription, the range of vision is 40-150cm. Thanks to the several strengths, you do not need to order different pairs of glasses for viewing different distances or frequently remove your glasses. The lenses are easy to get used to. Different manufacturers have different names for this type of lens, e.g. Traditional Office, Interview 080, or 130.

For smaller work environments, there are the so-called office work lenses, which provide concentrated vision within the distance of up to 4 meters and correspond to the needs of several professions, including chefs, doctors, musicians, artists, bookkeepers, car repair men, etc. These lenses enable to read near texts, view the computer screen, and the objects or customers/colleagues within the distance of up to 4 meters. Smooth vision is ensured in transition from near to medium distances. Different manufacturers have different names for this type of lens, e.g. Nova Office or Computer 3V. 

Accommodative lenses

Accommodative lenses are needed by shortsighted 16-40-year-old people wearing spectacles, whose eyes often get tired when using spectacles to read or work on the computer for prolonged periods of time.
Prices from 110 €/per pair. See the price list here.


On the bottom of the lenses, the minus is smaller or the plus higher – so the eyes do not get tense of constant viewing of near objects. Different manufacturers have different names for this type of lens, e.g. Nova Easy, Anti-Fatigue.
Before ordering lenses of an extended range of vision or accommodative lenses, you should consult an optometrist or an ophthalmologist to determine the precise range of strengths required.

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Optical sunglasses:

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Photochromic or automatically darkening lenses 

Photochromic or automatically darkening lenses are light indoors and darken outdoors depending on the UV light, while providing protection from bright light. Prices from 145 €/per pair. See the price list here.

Photochromic lenses can be installed in all frames, the selection of strengths and materials is very wide. Automatically darkening lenses come in three shades: gray, brown, and green. Thanks to the new technology, Chromea7, photochromatic lenses react better to direct as well as reflected light, even in very warm weather.

For this reason, the 7th generation of photochromic lenses is darker than the previous generation. The lenses reach the maximum level of darkeness outdoors, at the temperature of 23°C, gray lenses in the extent of 88%, brown lenses in the extent of 86%. In the case of warmer temperatures (e.g. 35°C), photochromatic lenses darken to darker shades than lenses of the previous generation (gray to 79% compared to 73% before; brown to 75% compared to 69%).
In the car, photochromatic lenses darken in the extent of 15%. The lenses darken quickly (a level of darkness of up to 70% is achieved in approximately 35 seconds). Returning to the light state depends on several factors, for example on the level of darkness reached outside, the temperature, and the optical strength. Returning to the completely light state may take 6-10 minutes. 

XTRActive lenses or lenses that darken in the car

XTRActive lenses darken in the car (by up to 50% at 27ºC) as well as outdoors (by up to 80% at 35ºC). Prices from 165 €/per pair. See the price list here.

Compared to the regular light lenses, the lenses have a barely visible shade indoors as well, which protects from bright light. Only available in gray shade. XTRActive lenses provide 100% protection from UVA and UVB rays and react equally well in cold as well as warm temperatures.

Automatically darkening Drivewear lenses

Drivewear lenses combine the vision free from distracting reflections achieved with polarised lenses and the best features of automatically darkening lenses that can adjust to light conditions. Prices from 335 €/per pair. See the price list here.

The glasses are not suitable for using indoors, as they take a greenish-yellowish shade approximately corresponding to the darkness category 2 in the conditions of low light or cloudy weather, which offers good contrast conditions and decreases the blinding effect of light. When driving a car, the lenses take a copperish shade, which improves seeing of colours and perception of depths. In the case of bright light outside, the shade turns dark reddish-brownish, which filters excessive light and ensures comfortable vision.

Tinted lenses

Sunglasses come in 5 different dimness categories, which are marked as categories 0-4.

Prices from 55 €/per pair. See the price list here.

Category 0 is the lightest, letting through the most light, and category 4 is the darkest, allowing only 5-8% of the light falling on the lenses to penetrate the lens. Category 4 lenses are not suitable for driving.

All tinted/coloured lenses purchased from the opticians are equipped with 100% UV protection, even the lightest lenses. When selecting sunglasses, attention must be paid to the dimness and shade of the lenses, since these characteristics determine how much light reaches the eye, whether of not there are distortions in how colours are seen, and how well contrasts are seen.

The neutral shades are gray, green, and brown, which means that they diminish the brightness of light, while leaving the colours natural. They are, above all, designed for decreasing the brightness of light and the stress on the eyes in the case of moderate and bright sunlight. The gray glasses seem darker than the brown ones. Brown and green distort colours a bit more than gray, but ensure better contrast. Yellow, golden, and amber shades provide a very good sense of contrast. Thus, these shades are ideal for skiiers, snowboarders, and for other winter sports. They even improve contrast in complex light conditions. Since the shades do not particularly decrease the brightness of light, they are mainly suited for the conditions of moderate and little light.

Pink and red shades make the world look more cheerful. They offer good visibility and increase contrasts in the case of little light and are thus ideal for skiing and snowboarding with cloudy weather. They also imporove the visibility of objects on blue and green backgrounds, which makes them well-suited for driving or using in a forest. Mirror coating reflects back most of the light falling on the glasses. Mirror coating makes observed objects appear darker than they actually are, thus, the coating is often used with lighter shades.

Mirror coating decreases the amount of light penetrating the lens by 10-60%, which makes it especially well-suited for the conditions with highly reflective surfaces: beaches, on the water, snowy conditions, high mountains, as well as for the people with sensitive eyes. The surface coating is highly vulnerable to scratches and is especially damaged by salty water. Thus, the lenses must be cleaned very carefully using special liquids and cloths designed for cleaning spectacles.

In the case of mirror lenses, the user may be more distracted by the reflections generated on the back surface of the lens than in the case of wearing regular sunglasses. For this reason, it is recommended to order mirror lenses with anti-reflective coating on the inside. In the case of spectacles with gradient lenses, the upper part protects from the brightness of light and the lower part allows to view near objects clearly, since the shade of the lens is lighter on the bottom.

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Polarised lenses

Polarised light is generated by reflected and scattered rays of light.

Prices from 135 €/pair. See the price list here.

Thus, the sharpness of both distant and near vision deteriorates, there might be an uncomfortable feeling or the feeling of tension in the eye. Polarised spectacle lenses are equipped with a filter, which blocks polarised rays of light and thus makes the vision through sunglasses clearer and sharper, while colour distortions are diminished to the minimum. Polarised lenses are the most beneficial for drivers and those interested in water-related hobbies. The colour selection includes brown, gray, and green (depending on the refractive index). The dimness corresponds to category 3. 

Convex sunglasses

There are various options when selecting sports sunglasses. The most inexpensive option is to buy a pair of sunglasses, which can be equipped with optical clips of the wearer’s correction on the inside of the frame. Another option is to order sports sunglasses from the manufacturer, selecting the wearer’s strength and a suitable model of frames. The third option is to order special convex glasses for selected convex frames, which ensure good vision, protection from bright light and from UVA and UVB rays.

Convex sunlenses from 140 €/per pair. See the price list here.

It is also possible to choose a suitable lens type, the shade and other characteristics which meet the needs of the wearer. It must be kept in mind that there are always small restrictions and recommendations for why it is not advised to use convex glasses on some occasions.
The specialists working at our stores will help you decide.

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Materials of spectacle lenses

Spectacle lenses are made of plastic, mineral glass, or polycarbonate. Plastic lenses are sold most frequently, because the advantage of the material in front of mineral glass is its lightness and breaking resistance, as well as the 90-100% UV protection. The advantage of polycarbonate is its impact-resistance, but the optical quality is the poorest compared to other materials.

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  • index 1.5 up to 50% lighter than mineral glass. Very good optical transparence. Resistant to smaller hot sparks from welding. Suitable for all frame types except rimless glasses. Very well suited for strengths of up to +/- 2.5 
  • index 1.53 the lightest plastic material and very good optical quality. 100% UV protection. Impact-resistant: the only plastic lens except the polycarbonate, which has passed the toughest impact-resistance and fast collision tests and corresponds to the ANSI Z87 standards. Durable and ideally suited for rimless spectacles (and regular spectacles). Trivex material is approximately 10% lighter, but also up to 10% thicker than polycarbonate. Due to the refractive index, very well suited for strenghts between +3.0... -3.0. 
  • index 1.56 20% thinner than lenses of the refractive index of 1.5  
  • index 1.59 30% lighter than a lens with the index of 1.5. Impact-resistant – passed the toughest safety tests in Europe and in America. Thus, the polycarbonate material is also used for making spectacles for children and for protective goggles. The poorest optical quality compared to other plastics. 100% UV protection.  
  • index 1.6 30% thinner than a plastic lens with the index of 1.5. Suitable for all types of frames, including rimless spectacles. Recommended from strengths +2.5/- 3.0. 
  • index 1.67 40% thinner than a plastic lens of the index of 1.5. Up to 6 times higher impact resistance. Suitable for all types of frames, including rimless spectacles. Recommended from strengths +3.0/- 4.0. 
  • index 1.74 50% lighter than a plastic lens of the index of 1.5. Up to 3 times lighter than mineral glass. Not suitable for rimless spectacles. In the case of high strengths, enables to make the thinnest and lightest glasses. The recommended lens type from the strenthts +/- 5.0.

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Surface coatings of lenses

In addition to the main material, lenses are covered with surface coatings in order to improve their resistance to scratches and decrease the amount of light reflecting back from the surface of the lens.

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Plastic materials are softer compared to mineral glass and thus more vulnerable to scratches.

In order to increase the scratch resistance, lenses are coated with hard surface coating. ~8% of light reflects back from the front and back surface of lenses. Reflections tire out the eye and decrease the clarity and contrast of vision.

In the case of anti-reflective surface coating, the amount of light reflecting back is 1-3%. Anti-reflective coatings, i.e. AR-coatings also make the lenses cosmetically more beautiful, because one can see the eye of the wearer, not distracting reflections through the lens.

In addition to the anti-reflective surface coating, it is possible to coat lenses with slicker coatings, which make them easier to clean, are anti-static, and dirt- and water-resistant.

Below are the explanations of the abbreviations of surface coatings: 

  • HC - hard coating. Placed on spectacle lenses in order to increase resistance to scratches. Does not provide 100% protection from scratches, thus the lenses must only be cleaned with products designed for this purpose. 
  • HMC - anti-reflective coating with hard surface. Decreases reflections from the inner as well as outer surface of the lens. 90% UV protection (up to 380nm). 
  • HMC+EMI - anti-reflective surface coating with hard surface and water-resistant antistatic surface coating. The surface coating is slicker and easy to maintain. 20% protection from the electromagnetic radiation originating from electronic devices. Decreases tiring of eyes. 
  • Satin- anti-reflective surface coating with hard surface and dirt- and water-resistant surface coating. 90% UV protection (up to 380nm). 
  • Satin (EP) - anti-reflective surface coating with hard surface and dirt- and water-resistant surface coating. The surface coating is slicker and easy to maintain. In order to protect the lenses from scratches which may occur in the course of grinding, the lenses are coverd with an additional protective film, which is removed before the lenses are delivered to the customer. Only available for the lenses in the stock. 90% UV protection (up to 380nm). 
  • Satin+ - anti-reflective surface coating with hard surface and dirt-and water-resistant antistatic surface coating. The surface coating is slicker and easy to maintain. In order to protect the lenses from scratches which may occur in the course of grinding, the lenses are coverd with an additional protective film, which is removed before the lenses are delivered to the customer. Only available for bespoke lenses. 90% UV protection (up to 380nm). 
  • Satin+Blue - anti-reflective surface coating with hard surface and dirt- and water-resistant antistatic surface coating. The surface coating is slicker and easy to maintain. 20% protection from the electromagnetic radiation originating from electronic devices. 100% UV protection (up to 400nm). The lenses with Satin+Blue coating are very well suited for the people who desire clearer and more comfortable vision and for those who spend most of the day working with digital devices. Viewing through lenses with Satin+Blue coating increases the contrast of the vision and eliminates distracting reflections. Less tiring on the eyes. Satin+Blue coating can be ordered for lenses from the stock or for bespoke lenses for plastic materials with refractive indexes of 1.5 and 1.6.

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Lens design

Two main designs are used in making spectacle lenses: aspherical and spherical.

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These words describe the convexity of the front or back surface of the lenses. In the case of speherical lenses, the whole front surface is of uniform convexity. The front surface of aspherical lenses is flatter. Aspherical lenses often also have higher refractive indexes. The combination of the two enables to manufacture thinner and lighter lenses. Aspherical design is very often used for making plus lenses, as plus lenses are thick in the middle. The higher the strength, the thicker the lens. Making plus lenses with aspherical design and of thinned material makes them thinner, the lenses are not visibly bulging out of the frame and, consequently, the spectacles are lighter.

Minus lenses are thin in the middle and thick on the edges. In the case of minus lenses, the difference achieved by using aspherical lenses is not that great as in the case of plus lenses. Still, the minus lenses with aspherical design are thinner than those of spherical design.

In the case of spherical lenses, natural distortion occurs when looking away from the centre, i.e. the middle of the lens. In the case of aspherical lenses, such distortion is smaller or eliminated and the clear field of vision is wider compared to spherical lenses.

Spherical lenses cause distoritions in the case of higher strengths. In the case of strong pluses, viewed objects seem larger and appear closer than they actually are and the eyes of the person wearing the spectacles also appear larger through the lens. In the case of strong minuses, objects seem smaller and the eye of the wearer also appears significantly smaller. Aspherical lenses diminish these effects.

Due to the flatter structure, only hard-surfaced aspherical lenses are affected by reflections which considerably distract the wearer. Thus, these lenses should always be ordered with anti-reflective surface coating. Due to the distortion of objects, getting used to aspherical lenses takes more time.

Spherical lenses are marked with the abbreviation SPH and aspherical with the abbreviation ASP in the price list.

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