Frequently asked questions

We accept most standard metal and plastic frames. The exception is certain frames, usually inexpensive metal ones, that are not designed for lens replacement. If you are unsure, send us a photo and we will check.

Yes. Your frames can be any brand, regardless of where you bought them.

Yes, although very old plastic frames can be more brittle and are slightly more likely, though still rarely, to crack during fitting.

Yes. For rimless and semi-rimless frames, you need to select a 1.61 or 1.67 lens index because these lenses are stronger and suitable for this type of fitting.

When they arrive, we inspect the material, screws, joints, temples and lens groove. If the frames are clearly at risk, usually because they are already weakened or cracked, we contact you before starting work.

We do not start production without your approval. We explain the reason, outline any available options and agree whether to return the frames or use another solution.

Yes. We return the old lenses together with your glasses.

Almost every prescription can be made in different lens indices; the main differences are thickness and weight. The highest index is not always the best choice because the visible difference between two indices can be minimal. You can send us your prescription and we will recommend the most suitable option personally.

Yes. If your prescription and chosen frames suggest that the lenses will be noticeably thick or heavy, we warn you before production.

Single-vision lenses contain one prescription power. Office lenses are designed for computer work and reading, covering intermediate to near vision. Progressive lenses cover all distances from far to near. Single-vision lenses have no peripheral blur, while all multifocal lenses do. The right choice depends on your prescription and how you use your glasses.

Your lenses include an anti-reflective coating to reduce glare, a hard coating to improve scratch resistance and a hydrophobic coating for easier cleaning. No coating, however, makes lenses indestructible.

Yes. Sunglass lenses and a range of special options are available, including polarised, tinted and photochromic lenses.

Photochromic lenses react mainly to UV light, most of which is blocked by a windscreen, so they usually darken less inside a car. The speed at which they darken and clear depends on the age of the lenses, the temperature and the light conditions.

Scratches and damaged coatings cannot be repaired. Unfortunately, the only solution is to make new lenses.

Our progressive, office and sunglass lenses use optical designs from the European company IOT. Our single-vision lenses are made in a factory owned by EssilorLuxottica. We sell the lenses under the Relenser brand rather than the manufacturers' brands.

Yes. Our lenses are comparable in quality to lenses that often cost two or three times as much at a traditional optician. The difference is our shorter supply chain, own-brand model and lower margins, not the quality of the lenses.

The difference is mainly the production range and complexity of the prescription, not the underlying quality. Standard covers common combinations of sphere, cylinder and addition, while Complex Prescription covers higher powers, prism or combinations that require special production. We check every order before production and contact you if the selected option is not suitable.

Our progressive lenses use free-form optical designs from IOT, an independent Spanish developer of progressive, office, single-vision and other lens technologies. We manufacture them under the Relenser brand and customise them to your prescription, frames and measurements.

The best current evidence does not show that blue-light-filtering spectacle lenses meaningfully reduce eye strain from normal screen use or protect the retina. Computer-related discomfort is more often linked to prolonged near focus, reduced blinking and dry eyes. We therefore generally recommend a good anti-reflective coating and healthy screen habits.

Our supply chain is shorter, we do not pay licence fees to use large corporate brands because we sell under the Relenser name, and our margins are lower than those of traditional opticians. This lets us offer comparable lens quality for around half the usual price.

During checkout, you can enter your prescription manually or upload it. You can also choose to send it later or ask us to read the prescription from the glasses you send us.

What matters is that you see well with the prescription we will make. We recommend having your eyes tested every two years.

For single-vision distance or reading glasses, we can read the required values from the existing lenses. We cannot do this for progressive or office lenses because they have already been optimised; optimising an already optimised prescription again could introduce an error.

That is not a problem.

Pupillary distance is the distance between your pupils and is needed to position the lenses correctly. You do not have to know or measure it yourself. We can obtain it from your old glasses, measure it from a photo, or use the value on your prescription if it is listed. If anything is missing, we will contact you.

To fit multifocal lenses correctly, we need the distance from your pupil to the lower edge of the frame. Before you send the frames, we therefore need a confirmed measurement or a photo taken according to our instructions. Without it, we cannot guarantee correct production.

Yes. We can make lenses from -20.00 to +20.00, with cylinders up to -10.00. We can also make prism lenses.

That is not a problem in itself. The eye with the stronger prescription determines the most suitable lens index. Send us your prescription and we can advise you on your specific case.

We guide you through every step of the order, and you can also contact us for personal advice. In general, we need your prescription; for suitable single-vision glasses, we may be able to read it from the lenses you send us.

Place the glasses in a hard case, then put the case in a box or padded envelope. Seal the parcel securely, remove any old labels and attach the GLS label we send you.

Shipping in both directions costs €2.99 in Slovenia and €4.99 in the other supported EU countries. GLS carriage and compensation are subject to the applicable terms and exclusions; this is not a promise of additional all-risk insurance. Standard service covers 25 EU countries, excluding Cyprus and Malta. For islands and special territories, contact info@relenser.com before payment so we can confirm both directions. Home collection is not currently offered.

Every parcel has a tracking number. We also send you an email when your frames arrive at our workshop.

Yes.

If you cannot manage without your glasses, contact us and we will include you in our pilot service for these situations.

Contact us as soon as possible. As long as lens production has not started, we can usually change or cancel the order.

If production is delayed, we notify you and provide a new estimated completion date. This can happen, for example, if a lens is damaged during edging and must be remade. If the carrier is delayed, first check the tracking information and then contact us so we can open an enquiry.

Unfortunately not. Relenser is available online only. If you would like to order lenses in person, you can visit a Della Spina optician in Ljubljana or Maribor.

Adaptation is usually quick with single-vision lenses. With progressive lenses, it can take more than a week. If the difficulties are not improving day by day, contact us.

Contact us within 30 days of delivery with your order number and a description of the issue. We first identify the cause and suggest an adjustment or lens remake. If we cannot find a suitable solution, we issue a refund.

Everything. If you are not satisfied with your lenses, we refund your purchase. Before issuing the refund, we only ask for proof that the lenses have been destroyed.

The warranty for manufacturing and material defects is two years. It usually covers issues such as peeling anti-reflective coatings or delamination of a polarising filter. Mechanical and heat damage, including scratches, impacts or heat-cracked coatings, is not covered. A separate 30-day satisfaction guarantee also applies.

It covers damage to your frames during the lens-replacement process. We replace new frames with the same model and used frames with new frames from our collection, which we choose together.

Use only a dedicated lens-cleaning spray. If the lenses are very greasy, you can rinse them with hand soap and lukewarm water, although this is not ideal for the frames. Do not use paper towels or disposable lens wipes, even if they are sold for glasses. They can be too abrasive and may damage the protective coatings over time.

Yes. We supply lenses and provide edging services to partner businesses. We hold a large stock of quality lenses, work exceptionally quickly and use modern machinery for highly precise processing. Contact us for more information.

In Slovenia, we stock 1.56 SHMC lenses from +4.50 to -5.00, 1.61 AS SHMC lenses from +5.50 to -6.00 and 1.67 AS SHMC lenses from 0 to -10.00. All are available with cylinders up to -2.00.

The lead time for prescription-made lenses is 72 hours.

Contact us for details about delivery regions and partnership options.

Yes. We provide the service for all types of frames.

Yes. We can store your frames in our warehouse.

By keeping your existing frames in use, we avoid manufacturing a new frame, its packaging, and part of the supply chain. New lenses still have to be manufactured, processed, and shipped, so we do not present the service as having no environmental impact.

Based on our internal estimate from March 2026, replacing lenses in existing frames saves approximately 3–4 kg CO₂e per order compared with buying a complete new pair of glasses. The estimate is based on publicly available eyewear life-cycle assessments and assumes that the customer would otherwise have bought a new frame with new lenses. The actual saving depends on the frame material, lens type, production, and transport distance. The estimate has not yet been confirmed by a company-specific LCA under ISO 14040/14044 or by independent verification.

We compared the estimated impact of buying new glasses with replacing the lenses in an existing frame. We considered frame manufacturing, lens manufacturing and processing, packaging, and shipping the glasses in both directions. This is an internal Relenser model from March 2026, based on publicly available optical-industry data. We will update the model when we obtain more precise supplier data and our own independent life-cycle assessment.

Our internal estimate for an approximately 150-gram parcel sent by road is about 25 g CO₂e for a typical return shipment within the EU and up to about 54 g CO₂e for a longer return shipment, for example from Spain or Portugal. The estimate uses an emission factor of 120 g CO₂e per tonne-kilometre and a total transport distance of 1,400 to 3,000 kilometres. The actual impact depends on the carrier, route, and delivery method.

According to our internal estimate, no. The estimated impact of return shipping is approximately 0.025–0.054 kg CO₂e, while the estimated benefit of keeping the frame amounts to several kilograms of CO₂e. This is a modelled estimate, not a measurement of an individual shipment, and it may not include all emissions from the carrier, warehousing, and the final delivery stage.

The circular economy gives priority to extending product life, reuse, and repair over replacing the entire product. At Relenser, we keep the usable frame and replace only the lenses that no longer serve their purpose because of a changed prescription or damage.