Prescription Lens Guide | Prescription, PD & Progressives

Easy from the first step

From your prescription to glasses ready to wear

You don't need to understand everything before you start. The process is designed so you can complete your purchase even if you're unsure about a value on your prescription.

1

Choose a frame

Open a model that offers the prescription lens option.

2

Add your prescription

Upload a photo of your prescription or enter SPH, CYL, AXIS, ADD and PD where applicable.

3

Customise your lenses

Choose vision type, brand, index, coating and the available colour options.

4

We check and manufacture

We check the necessary information before sending the lenses to production and fitting them.

What do I need to buy?

Start with what you already have

One of the most common worries is thinking you need perfect information before you can begin. That's not the case.

The easiest option

I have a photo of my prescription

Upload it during checkout. We'll use it to check your prescription details before manufacturing.

Also valid

I know how to enter the details

You can fill in your prescription manually. If your PD has decimals and the form doesn't accept them, share the exact value in the notes or with our team; there's no need to round it yourself.

We'll help you

I'm missing some information

You can proceed and check with us. For progressive lenses we'll also need the ADD value and the corresponding centring measurements before manufacturing.

How to read your prescription

The abbreviations look complicated. In reality, it's just five values.

Prescriptions can come in different formats, but the main fields repeat. Look for these abbreviations or their equivalent names.

Don't confuse: a contact lens prescription isn't always the same as a glasses prescription. If you're unsure about the document you're about to send, check with us before we go into production.

SPH

Sphere

Indicates the main correction for short-sightedness (–) or long-sightedness (+).

CYL

Cylinder

Indicates the amount of astigmatism correction. May also appear as CYL.

AXIS

Axis

Marks the orientation of the astigmatism, usually between 1° and 180°. CYL and AXIS always go together.

ADD

Addition

Extra power for near vision. A required value on progressive or bifocal prescriptions.

PD

Pupillary distance / PD

Used to optically centre the lenses in front of your pupils. May appear as a single total value or as one value per eye.

OD/OS

Right eye / left eye

Depending on the prescription format, you may also see OD/OS written this way.

Pupillary distance

Can't find your PD? It's one of the most common questions.

Your PD is used to position the optical centre of each lens in front of your eyes. It doesn't always appear printed on the prescription.

PD

It may be on your prescription

Look for “PD”, “pupillary distance” or “interpupillary distance”. It may appear as a single number or as two values, one for each eye.

↔

If it isn't, it can be measured

During checkout you can use a measuring app to get your PD directly. If you prefer, you can also provide a measurement taken previously. For progressive lenses we'll also need the fitting height.

Does your PD have decimals? If you received values such as 34.9 / 34.6 mm and the form only accepts whole numbers, don't round them yourself. Share the exact value in the notes or with our team so it can be taken into account during production.

One lens · several distances

Distance visionNear vision

The geometry of a progressive lens requires more precise centring than a single-vision lens.

Progressive lenses

Yes, you can order progressive lenses online

All our prescription glasses can be configured with progressive lenses. For them to work correctly, we need the right centring measurements before manufacturing.

Your full prescription, including ADD.
Pupillary distance (PD).
Fitting height adapted to the frame.
The chosen frame is prepared with the configuration needed for progressive lenses.

We don't recommend replacing these measurements with a ruler estimate. During checkout you'll be able to use the available measuring app to get your PD and complete the necessary measurements before production.

Shop progressive glasses →

Choosing your lenses

You don't need to be an optician to choose well

First decide how you see; then we optimise thickness, coating and technology based on your prescription, your frame and your daily use.

Decision	What it means	When it makes sense
Single-vision	A single main correction across the whole lens.	Distance or near vision with a single prescription.
Progressive	Combines distance, intermediate and near vision in the same lens.	When your prescription includes ADD and you need several distances.
High index	Higher-index material to reduce thickness at certain prescriptions.	Higher prescriptions, or when the goal is a thinner, lighter lens.
Anti-reflective coating	Reduces reflections on the surface of the lens.	Daily use, screens, driving and a cleaner look.
Photochromic / Transitions	Darkens with UV exposure and clears again indoors.	For anyone who wants a versatile lens between indoors and outdoors.
Polarised	Reduces glare reflected off surfaces such as roads or water.	Especially useful for sunglasses and daytime driving.

ZEISS lenses INDO lenses Oakley RX

Photochromic / Transitions

They darken depending on exposure to outdoor light.

Photochromic lenses react mainly to UV radiation. A windscreen filters out much of that radiation, so a conventional photochromic lens doesn't activate the same way inside a car.

If driving is your priority: consider prescription sunglasses or polarised lenses. We'll help you choose the right option depending on the model.

☀

Outdoors

UV exposure activates the darkening of the lens.

CAR

Inside the car

The windscreen reduces the UV radiation needed for the usual activation.

Prescription sunglasses

Your sunglasses, with your prescription

When a model's product page offers the prescription option, the lenses are made to your prescription and fitted into the frame before shipping.

Available colours, polarisation and technologies depend on the model and supplier.
Custom manufacturing may add a few days to the standard delivery time.
If you're looking for original lenses from the brand itself — Ray-Ban or Maui Jim, for example — confirm this before buying: it shouldn't be assumed if the product page doesn't state it explicitly.

Shop prescription sunglasses →

SUN RX

Exact availability depends on the combination of frame, prescription and lens technology.

Before they reach your hands

We don't send your prescription straight to production without checking it

Trust doesn't just come from selling a good lens. It comes from checking that the information needed for that lens and that frame is complete.

01

Data review

We check that the prescription contains the fields required for the chosen lens type.

02

Centring and fitting

PD is used for optical centring; for progressive lenses, the necessary fitting measurements are also included.

03

Manufacturing and fitting

Custom lenses are produced and fitted into the frame before shipping.

Before you buy

Special cases, explained with no small print

These are the doubts that most easily block a purchase when they aren't clear from the start.

Do I want just the frame?

Yes. If you don't select prescription lenses, you can buy the frame alone with the corresponding demo or factory lenses.

Can I send in a frame I already own?

No. For warranty and quality-control reasons, our lens-fitting service is only carried out on frames purchased from Bassol Optic.

My prescription includes prism

Prism correction shouldn't be assumed to be a standard option. Contact us before buying to confirm feasibility depending on the supplier, prescription and frame.

I need an invoice for insurance

To issue the invoice we'll need the account holder's national ID/tax ID number. Just the number; there's no need to send a photo of the document.

Can I return prescription lenses?

Lenses are made to order and, as a result, don't follow the return policy of a standard product. Check the conditions that apply to custom-made products and the standard cover for manufacturing defects before buying.

Is there a current promotion?

Campaigns change. Always check the banner or the conditions currently in force on the website to confirm dates, amount, and whether the discount applies to the frame, single-vision or progressive lenses.

Frequently asked questions

What you need to know before getting prescription glasses online

Can I send a photo of my prescription?

Yes. You can upload a photo of your prescription during checkout or enter the details manually. The necessary information is checked before the lenses are manufactured.

What do SPH, CYL, AXIS, ADD and PD mean?

SPH is the sphere; CYL and AXIS describe the astigmatism correction; ADD is the extra near-vision power used in progressive or bifocal lenses; and PD is the pupillary distance used for optical centring.

My PD has decimals and the form doesn't accept them. What should I do?

Don't round it yourself. Share the exact measurement in the notes or with our team so it can be taken into account during the process.

I don't have my pupillary distance. Can I still buy?

Yes. During checkout you can use the available measuring app to get your PD. We'll need this measurement before manufacturing the lenses.

How are the measurements taken for progressive lenses?

Besides the prescription and PD, progressive lenses require the correct fitting height. We'll guide you through the process to get the necessary measurements; PD can be measured with the app built into the checkout process.

Can all prescription glasses be made progressive?

Yes. All our prescription glasses can be configured with progressive lenses. During the process the necessary measurements are requested to carry out the centring and fitting correctly.

Do ZEISS and INDO lenses offer UV protection?

According to our product guide and customer service, the lens brands we offer include full UV protection as standard. The differences between ranges lie in optical design, coatings, materials and available options.

Do photochromic lenses darken inside a car?

A conventional photochromic lens doesn't activate the same way behind a windscreen because it blocks much of the UV radiation needed. For daytime driving, prescription sunglasses or polarised lenses may be more suitable.

Are prescription sunglasses original from the brand?

It depends on the model and supplier. If you're specifically looking for an original lens from a brand — Ray-Ban or Maui Jim, for example — confirm this before buying if the product page doesn't state it explicitly.

Can I buy just the frame?

Yes. You can buy the frame without selecting prescription lenses.

Can you fit prescription lenses into a frame I already own?

No. For warranty and quality-control reasons, we only fit prescription lenses into frames purchased from Bassol Optic.

My prescription includes prism. Can you make it?

It needs to be checked before buying. Prism shouldn't be considered a standard customisation available with every supplier or frame; contact our team with your prescription and the model you're interested in.

How do I request an invoice for my insurance?

We'll need the order holder's national ID/tax ID number. Just the number, with no need to send a photo of the document.