B Sunglasses Guide to Prescription Sunglasses

B Sunglasses, as of September 2013 are selling prescription sunglasses and prescription glasses as part of our designer eyewear services. You can now order your prescription to be added to your favourite designer brand frames including Ray Ban, Tom Ford, Stella McCartney, Oakley, Carrera,  Versace, Lacoste, Police, Miu Miu and Gucci. Here is our Guide to choosing the right prescription with B Sunglasses

What is a prescription?

A prescription is usually determined by your optician after an eye test. This indicates which lenses you should be using to see more clearly. However, spectacles have become more of a fashion statement over the years with a number of styles and shapes to choose from as well as frames with designer brands. For this reason, prescription sunglasses have been introduced by a number of establishments and now B Sunglasses are offering this service for a competitive price on our designer frames.

You can now pick up a pair of Prada, Ray Ban or Celine sunglasses with a prescription lens tailored to your needs.

Why choose prescription sunglasses?

Prescription sunglasses are useful because they serve multiple purposes in one frame. Never again will you have to swap shades or put your sunglasses over your regular glasses to see. Prescription sunglasses serve the function of providing UV protection and shade in harsh sunlight as well as giving clearer vision that prevents you from straining your eyes; all of course tailored to your needs.

Of course you can also buy our designer frames and have clear prescription lenses fitted to make a real style statement at a reasonable price.

Filling in the prescription form

Now when you go to make a purchase on B Sunglasses, you have the option of adding a prescription. Clicking this link will bring up a form to fill in your prescription details. You must know these details prior to placing your order. You must fill out the form in full as these details need to be accurate as possible for our resident Optician to get your order right. We source all our finely crafted lenses from Switzerland and they are treated and applied by a highly trained team of Optical specialists.

Prescription details used to complete the prescription form must have been provided by a registered optician or eye specialist within the last 12 months. It’s the customers’ responsibility that the prescription given is in date. You may email us a copy of your prescription if you are unsure how to enter your details.

See below for information on how to enter you prescription.

Providing Prescription Lenses

Once ordered, you must be aware that our prescription service will hold up your order for a few days therefore our Next Day Delivery service does not apply. We aim to have these dispatched within seven to ten working days of purchase (perhaps slightly longer if ordering from overseas) if ordered before 4pm.


What is the SPH / Sphere?

The sphere (Sph) specifies the strength of lens required to correct your focus.

A plus (+)  sphere will correct long-sightedness. This is otherwise known as ‘hyperopic’ which indicates as difficulty focusing on close object. A minus (-) sphere will correct short sightedness which is also known as Myopia; difficulty focusing on distant objects.

The sphere is measured in Dioptre’s (which determines optical power). Your prescription may have the word Plano or Pl or an infinity sign which means that you are neither long nor short sighted but require zero power for the Sphere. Most values range from 0.00 to +/- 20.00 and go up in steps of 0.25.

What is the CYL / Cylinder?

The CYL and AXIS compensate for astigmatism. Astigmatism is where the eye is shaped slightly like a rugby ball. This can be referred to as ‘toric’ i.e. not a perfect spherical shape. This usually results in the the eye having difficulty focusing at certain angles.

This box maybe empty or have a plus or a minus value in it. The measurement is the Dioptre. Most values range from +/- 0.25 to +/- 4.00 and will go up in steps of 0.25.

What is the AXIS?

The AXIS is only present if there is a value in the CYL box. The AXIS tells us where the astigmatism is on your eye. The measurement is in Degrees. The values range between 0 and 180 and may go up in steps of ½, 1, 5 or 10 degrees. We only show the AXIS to a whole number but if you have a ½ degree on your prescription you can list this in the additional information box when ordering.

The Add, short for Reading Addition, is the additional correction required for reading, this can be used to make either reading glasses, bifocal glasses or Varifocal glasses.

This figure is an indication of how much extra power is required in addition to the distance prescription for near or intermediate glasses. This extra power will ALWAYS be the same for each eye and may only appear once on your prescription but it is understood to be meant for both eyes. The measurement is the Dioptre, and most values range from +0.50 to +3.50 and will go up in steps of 0.25.

The ‘addition’ is only required if the glasses are going to be used for reading or close work. If your glasses are for distance only, this will not be an issue. Sometimes opticians use the word ‘Add’ or ‘Near’ instead of ‘addition’. They may only write it once, but it normally applies to both eyes and is almost always the same value for both eyes (e.g. ‘Add’ +2.50 – should be entered for both eyes).

What is the PD a.k.a. Pupillary Distance?

This is the difference in measurement between the pupils in each eye whilst looking straight ahead. You can contact your optician for this measurement.

On average the PD in an adult is usually between 60 and 66 millimetres. 63mm is the average Pupillary Distance (PD) but we advise that you get this from your optician.

Choosing Frames

Try and choose a frame that compliments your face shape as well as your skin tone, hair colour and hair style. You can find our Face Shape Guide here to help make your decision or alternatively try on a similar style in a local store to get a feel for what shapes suit you. That way you can make an informed decision before making your purchase with us and committing to your sunglasses prescription.
All prescription sunglasses and glasses are custom made and are not returnable for refund or exchange.

Lens Size

Standard size lenses are suitable for low prescriptions but for those with higher, stronger prescriptions, standard lenses tend to be thicker and heavier. This usually means they are uncomfortable and not as attractive to wear. For those with higher prescriptions, customers should choose High Index/Thin lens as they are lighter on the nose and more attractive, making glasses much more comfortable to wear.


  • 1.49 Index is suitable for prescriptions with Sphere values from Plano to +/- 3.00
  • 1.56 Index is suitable for prescriptions with Sphere values from +/- 3.00 to +/- 3.75
  • 1.61 Index is suitable for prescriptions with Sphere values around +/- 4.00
  • 1.67 or 1.74 Index is suitable for prescriptions with Sphere values above +/- 4.25 it would be ideal for 1.67 or 1.74 index

Lens Coatings

We include UV Protection lenses, Clear prescription, Gradient lenses and Polarised. We can match the lenses in the glasses of your choice by colour however you can also select lenses in different hues ranging from clear to brown, grey or green in either full coloured or gradient. Most of our prescription sunglass lenses are UV protected due to protective coating which stops the UV light from penetrating and potentially damaging your eyes. As many of our sports design sunglasses do come with a polarised filter (that gives extra clarity and reduces glare) this can also be specially requested when treating your lenses

For any queries regarding the B Sunglasses prescription service feel free to contact: prescription@B Sunglasses.co.uk