Thin Lenses for Strong Prescriptions: What You Are Actually Paying For
5 October 2026
12:20
Yes, in most cases you can put new lenses in old frames. It’s called reglazing: we remove your old lenses, then cut new ones to the exact shape of your frame and fit them. It works well as long as the frame is in good condition and suits your prescription.
I’m Rahillah Moghul, an Independent Prescribing optometrist and the owner of Mosspark Opticians in Glasgow. We reglaze frames regularly, including ones bought elsewhere. This guide covers when reglazing is a good idea, when it isn’t, what to know about varifocals, and what affects the cost.
Reglazing is usually a good option when:
Plastic frames become more brittle with age, and heat makes this worse. A frame that has spent years in a warm car or on a sunny windowsill is more likely to crack. Fitting new lenses usually means gently warming the frame, so an old, brittle frame can break. Rimless frames, where the lenses are held by screws through drilled holes, can also be weakened by repeated reglazing.
If a frame means a lot to you, for example it belonged to someone close to you, talk to us first. Sometimes the right advice is to keep it safe and choose a new frame for your new lenses.
Frame type | Reglazing outlook | What to know |
|---|---|---|
Full-rim acetate, good condition | Usually straightforward | Needs heating; small risk of cracking if brittle |
Full-rim metal, good condition | Usually straightforward | Check screw threads and rim wire condition |
Semi-rimless (nylon cord) | Possible, moderate risk | Groove must be cut precisely; cord may need replacing |
Rimless (drilled) | Higher risk | New holes in new lenses; mount may not survive |
Frame over roughly five years old | Assess individually | Acetate dries out and becomes brittle with age |
Frame with existing crack or repair | Not advisable | It will almost certainly fail during glazing |
Designer frame, discontinued | Often worth it | The reason most people ask in the first place |
The single biggest factor is not the frame type. It is age and condition. A five-year-old acetate frame that has lived in a car in Glasgow winters is a different proposition from the same frame kept in a case.
Worth understanding, because it explains where the risk comes from.
The new lenses are cut and edged to match the shape of your frame, then fitted. For a plastic frame, that means heating it until it flexes enough to accept the lens, and heating is the moment of danger. Acetate dries out over years; an older frame can become brittle without looking any different from the outside. It goes into the heat looking fine and comes out with a hairline crack.
For rimless frames the lenses are drilled and mounted directly, which means new holes in new lenses and reusing mounting hardware that has already been through this once. For semi-rimless, a groove is cut around the lens edge to take a nylon cord, and that groove has to be exactly right.
No optician can guarantee an old frame against breakage during reglazing. Anyone who does is either not being straight with you or is quietly pricing the risk into the job. We will tell you our honest assessment before starting, and it is your decision from there.
Often, yes, but varifocals need more care. The reading area sits at the bottom of the lens, so the frame needs to be deep enough to fit it, or reading will feel cramped. The lenses also have to be positioned exactly, using measurements of where your pupils sit when you wear that particular frame.
This is why varifocal reglazing should be done in person, not by post. We take the fitting measurements with your frame on, and adjust it first so it sits correctly. Our guide to varifocal lenses explains how they work, and our 30-day varifocal guarantee gives you time to adapt.
Reglazing is a good chance to upgrade the lenses. Options include:
Blue-light filters are also available, although the evidence that they reduce eye strain is limited. I’ve explained why in blue light glasses: the myths. You can see all the options on our advanced lenses page.
The cost depends mainly on the lenses, not the frame. Single vision lenses cost less than varifocals, and extras such as thinner lenses, coatings and tints add to the price. We give you a full quote before ordering anything.
If you qualify for an NHS optical voucher, you can usually put it towards new lenses for your own frames. You can check who qualifies for help with glasses.
Reglazing isn’t always the cheapest option. If you want a second pair anyway, our 2nd pair half price offer can work out better value than reglazing an old frame.
Reglazing makes sense if you love your frame, it’s in good condition, and it suits your new prescription.
New frames make more sense if your frame is cracked, loose or brittle, it no longer fits well, or your prescription would make the lenses thick and heavy in it.
There’s also a middle option: keep your old frame as a spare or turn it into prescription sunglasses, and choose something new for everyday wear. If you’d like to see what else might suit you, have a look at our independent and designer frames.
Your frame stays with us while the lenses are made, so bring a spare pair of glasses if you have one. We’ll tell you the timescale when you order.
To find out whether your frames can be reglazed, call Mosspark Opticians on 0141 427 4040, or bring them in to 115 Airth Drive, Bellahouston, Glasgow G52 1JU.
Entirely fine, and we would rather say so plainly than leave people wondering.
Your prescription belongs to you and you can have glasses made wherever you like. If you bought frames online or from another practice and want them reglazed here, bring them in. We will assess the frame honestly, tell you whether we think it will survive, and quote for the work.
The same applies to adjustments. If your glasses are uncomfortable and you did not buy them from us, we will still adjust them.
Sometimes the economics do not work, and it is worth being candid about it.
If the frame is old, the prescription has changed substantially, and the lenses need to be a premium design, you can end up paying a significant amount to put expensive new lenses into a frame that may fail and has limited life left regardless. At that point, new frames with the same lenses is often the more sensible purchase.
We will tell you when we think that is the case. If you want to proceed anyway because you love the frames, that is a perfectly legitimate reason and we will do the work. Our frame range and the brands we stock are deliberately curated rather than vast, and there is a free styling consultation if you would rather have help choosing.
If you want to understand the numbers on your prescription before you come in, understanding your glasses prescription breaks it down.
Book your comprehensive eye examination or eyewear styling consultation with
Mosspark Opticians today.
Usually, yes. This is called reglazing. As long as the frame is in good condition, with no cracks, loose joints or warping, new lenses can be cut to its shape and fitted. We check your frame before ordering anything.
It depends mainly on the lenses rather than the frame. Single vision lenses cost less than varifocals, and extras such as thinner lenses, anti-reflection coatings or tints add to the price. We give you a full quote before ordering.
In most cases, yes. We can fit new lenses to frames bought elsewhere, including online, as long as the frame is sound and suits your prescription.
It is uncommon, but it can happen, especially with older plastic frames that have become brittle, because fitting often involves gently heating the frame. We check the frame first and tell you honestly if we think it is at risk.
Often, yes, but the frame needs to be deep enough to fit the reading area, and the fitting heights have to be measured with the frame on your face. That is why varifocal reglazing is best done in person rather than by post.
If you qualify for an NHS optical voucher, it can usually be put towards new lenses for your own frames. Ask us at your appointment and we will check what your voucher covers.
Often yes, and it is the most common reason people ask. If the frame is discontinued, suits you well and is in sound condition, reglazing keeps something you cannot replace. Weigh it against the frame’s age and whether your prescription has changed enough to need a lens the frame cannot carry well.
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