If you wear glasses and you need ballistic or sealed eye protection, you have three options: contact lenses, a full prescription safety frame, or a prescription insert. The insert is the cheapest route and the most flexible, because it clips inside protective eyewear you already own. What catches people out is that an RX insert arrives empty. It is a carrier, not a finished pair of glasses, and getting lenses into it is a job for your optician.
This guide covers what that actually involves in the UK.
What an RX Insert Is
An RX insert is a lightweight carrier shaped to sit inside a specific goggle or pair of glasses. Your prescription lenses are edged to fit the carrier, and the carrier sits behind the protective outer lens. That is true of every RX insert, whatever the model. The outer lens keeps doing its job, and your correction sits behind it.
The reason this exists is that ballistic and sealed eyewear is wrapped and curved, often to Curve 5 or Curve 6. Grinding a strong prescription into a lens with that much wrap causes distortion. Putting the prescription on a flat carrier behind the lens sidesteps the problem entirely.
Two things to be clear about before you buy.
- The insert comes empty. No lenses, no prescription. Budget for the lenses and the optician's glazing work on top.
- The lenses your optician fits are standard prescription lenses, not certified safety lenses. All of the impact and ballistic protection comes from the outer lens of the goggle or glasses. The insert sits behind it and is not itself rated to any safety standard.
That is exactly how inserts are designed to work, and it is why you must always wear the eyewear with its outer lens in place. An insert on its own is not eye protection.
The Process, Step by Step
- Buy the insert for your specific eyewear. Inserts are not universal. The one made for the Chronosoft will not fit the X1000.
- Phone your optician before you go. This is the step people skip and regret. Glazing a carrier a customer brings in is routine work for most opticians, but not all of them will do it. More on that below.
- Take the physical insert with you. Your optician needs the carrier in their hands to trace its shape and edge the lenses to match it. Sending a prescription by email is not enough.
- Hand over your prescription details. The full set, not just the sphere figures. See the table below.
- Consider polycarbonate. Your optician will glaze the insert with ordinary prescription lenses. Polycarbonate is worth asking about because it is light and hard-wearing, which matters when the lens is sitting close to your face behind a goggle lens. It does not make the insert a safety lens.
- Collect and fit. Once glazed, the insert clips into the eyewear and lifts back out for cleaning.
What Your Optician Needs From You
| PD (Pupillary Distance) | The distance between your pupils, used to centre the lenses correctly in the carrier |
|---|---|
| SPH (Sphere) | The main correction for short sight or long sight |
| CYL (Cylinder) | Astigmatism correction, if your prescription includes it |
| AXIS | The orientation of the cylinder correction, in degrees |
| ADD | The reading addition, if your prescription has one |
| The insert itself | Required. The carrier has to be traced and the lenses edged to its exact shape |
A UK sight test prescription is valid for two years for most adults. If yours has expired, get retested before ordering lenses, because glazing to an out-of-date prescription wastes the lenses as well as the fee.
Will Any Optician Do It?
Most will, but not all, and the difference matters before you make a trip.
Independent opticians are generally the most straightforward. Glazing supplied frames and carriers is normal work for them and many have an in-house edging lab.
Boots Opticians, Vision Express and most other chains will usually glaze eyewear you supply, provided it is in sound condition.
Specsavers is the notable exception. Their general position is that they will not glaze frames not bought from them, on the basis that they cannot replace an item they did not supply if it is damaged during the process.
None of that is a rule set in stone, and individual branches vary. One phone call saves a wasted journey.
Single Vision, Varifocals and Prescription Limits
Single vision is the sensible default. The lens area in an insert is small and sits close to the eye, which leaves very little room for the corridor a varifocal needs. Bifocals and varifocals are not impossible, but discuss them with your optician before you commit rather than assuming they will work.
There is a practical ceiling on prescription strength. Bolle describes its inserts as suited to weak to medium prescriptions. Strong corrections produce thick, heavy lenses, and behind a goggle lens that means weight, reduced eye relief and a greater chance of contact between the two lens surfaces. If your prescription is strong, ask your optician whether an insert is realistic before you buy one.
Which Insert Fits What
Inserts are model-specific. These are the ones we stock and the eyewear each one belongs to.
| RX Insert for Chronosoft Goggles | Fits the Bolle Chronosoft Ballistic Goggles, both sealed and vented versions |
|---|---|
| RX Insert for X1000 Goggles | Fits the Bolle X1000 Ballistic Goggles |
| RX Insert for Combat Glasses | Fits the Bolle Combat Ballistic Glasses Kit |
Because every insert sits behind the outer lens, one glazed insert serves every lens in a multi-lens kit. On the Combat kit or the X1000 three-lens kit you swap the outer lens to suit the light and the prescription stays exactly where it is. Glaze once, use it with all of them.
Looking After a Glazed Insert
Take the insert out to clean it rather than trying to reach it in place. Rinse first to lift grit, then use a lens cloth. Dry cloths dragged across dusty lenses are the main cause of scratching. Store the eyewear in its case with the insert fitted so the two are never separated.
Worth knowing for warranty purposes: scratches and damage from use are not manufacturing defects, so they are not covered under the standard two-year Bolle guarantee.
The Bottom Line
An RX insert is an empty carrier that takes ordinary prescription lenses and sits behind the protective outer lens, which is where all the certified protection comes from. Buy the one made for your eyewear, ring an optician who will glaze supplied carriers, take the insert in with your full prescription including PD, and go single vision unless your optician advises otherwise. Done that way it is a straightforward job, and a good deal cheaper than a dedicated prescription safety frame.