Thin lenses

Thin and light plastic and glass lenses

Thin plastic lenses

You have likely found us because you have a higher strength or complex prescription. We can provide a reglazing service to put new thin, aspheric, double-aspheric or glass lenses into your own frame. We can cater for high strength prescriptions ranging from -30.00 to +25.00!

We offer a comprehensive range of premium high index spherical, aspheric and double aspheric (also known as bi-aspheric) from Zeiss, Seiko and Tokai. We also offer Zeiss SV Superb which are even more precise than a double aspheric because they are manufactured using point-by-point optimisation across the entire lens.

Thin glass lenses

For glass lenses we only offer premium Zeiss single vision (SV) glass range in 1.6, 1.7, 1.8 and 1.9. All Zeiss glass lenses come complete with the Zeiss Super ET anti-reflective coating.

Glass is thinner than plastic, so a 1.6 glass lens will be thinner than a 1.6 plastic lens of the same power despite them being the same index. Glass is also more durable than plastic, but it is heavier.

Buying stronger prescription lenses online

Please check that our standard lens reglazing prices are not cheaper. We provide 1.5, 1.53, 1.6 and 1.67 in our standard lens prices. We just offer the same indexes, with the inclusion of 1.7, 1.76 and 1.6, 1.7, 1.8 and 1.9 Glass in a larger range on our specialist aspheric, double aspheric (Bi-aspheric) and glass reglazing services.

Aspheric, double aspheric and bi-aspheric?

Double aspheric and bi-aspheric are the same thing. This means, when the lens is made, both front and back surfaces of the lens are surfaced with an irregular curve, making the lenses even flatter and thinner than a standard aspheric lens. Aspheric lenses are only surfaced on the front surface of the lens.


Spherical lenses

Spherical lenses are the standard lenses used in prescription glasses on standard 1.5 index and 1.6 index. It is when the lenses are 1.67 or above that they are usually aspheric in design by default.

Spherical lens sphere power recommendation: Up to and including -/+3.00.


Aspheric lenses are slimmer and flatter than conventional lenses. This is most noticeable for those with far-sighted vision (‘plus’ powered lenses). They are thicker in the middle and thinner at the edge. By using an varying curve on the front surface, aspheric lenses help to flatten and minimise the bulge which often protrudes outwards from the front of the frame.

Aspherical lens sphere power recommendation: from -/+3.00 to +/-6.00

Double Aspheric

Double/Bi aspheric lenses

Double aspheric or bi aspheric (same thing!) lenses will greatly benefit wearers will higher sphere powers and especially those with astigmatism (if you have cylinder values on your prescription). The lenses help to reduce the magnification of the eye for plus powers (far sighted) and reduce minification for minus powers (near/short sighted). When combined with a higher index lens, double / bi aspheric lenses are the best lenses available for improving the cosmetic appearance of your lenses.

Double / bi aspheric lens sphere power recommendation: greater than +/-6.00

The lenses we can supply

In-house Aspheric

These lenses are conventionally surfaced and come complete with a scratch resistant and anti-reflective coating. They are also UV safe.

Spherical / Aspheric / Superb

Zeiss spherical lenses are good for lower prescriptions but aspheric are better when it comes to performance for higher prescription powers. Spherical will still be a great lens if you are looking for thinner lenses on a budget.

AsphericZeiss AS‘ lenses have a flatter front curvature and are thinner than a spherical lens of the same power.

Zeiss single vision Superb lenses are made using more precise freeform technology (read more). This gives better clarity and visual performance across the entire lens.

All Zeiss lenses come complete with Zeiss Duravision Platinum UV coating.

Read more on the official Zeiss website

Double Aspheric

Manufactured using Seiko Digital Surfacing.

Sharper and improved clarity across the entire lens. Minimising astigmatic aberrations (great for those with higher cylinder (CYL) powers. Enjoy relaxed vision across a thinner lens, while also benefitting from the reduction in magnification of the eye for those with PLUS (far-sighted/long-sighted) prescriptions.

All Seiko lenses come with the choice of the Seiko SRC (SuperResistantCoat) or SRB (SuperReducedBlue) coatings.

Read more on the official Seiko website

Lutina / Bi-Aspheric

Ocular diseases are believed to be caused by oxidative stress. Lutein is one of three carotenoid pigments and without a sufficient amount of lutein protecting the macula this can lead to an increased risk of AMD (Age-Related Macular Degeneration). AMD is the most common cause of vision loss in those aged 50+.

Tokai Lutina lenses have the ability to absorb light in the ranges of 400nm – 420nm. This is the range for high energy violet light. By cutting out 94% of this light the Lutina lenses can help to preserve optical health.

All Tokai lenses come with either the NRC (No Reflection Coating) or the PGC clean multi coating which is super-oleophobic and easy to clean.

Read more on the official Tokai website

The manufacturing process


lens reglazing

We use a focimeter to measure the optical centres of your existing lenses.

We mark the lenses at these points and that tells us your exact pupil distance measurement and if the lenses have a fitting height measurement (where the optical centre of the lens is set directly in front of your pupil, rather than on the horizontal centre line of the frame).

Set and cut

lens reglazing

When the lenses are still in the uncut stage i.e. not cut to the shape of your frame yet, we set the axis of your lenses on a blocker, and we then put the lenses into a lens edger.

We then guide the bevel of the lens to be in the best position for the lens thickness and the curvature of the frame. This is a very important step with high minus lenses.


lens reglazing

We then fit the lenses to your frame.

With plastic frames, they are heated to allow the lens to slot into the rim easily.

With high minus lenses, this is the stage where an edge chamfer may need to be added, by hand, to give the best aesthetic appearance.


lens reglazing

This is very similar to the first step when we measured your pupil distance.

We put the frame, complete with the newly fitted lenses, back onto the focimeter and check the powers are correct, the pupil distance and fitting heights are correct, that there are no marks on the lenses and that the frame is set up squarely.

The frame then passes inspection and is ready for dispatch.


Why will you not sell a new frame with high prescription lenses?

This is very simple. With stronger prescriptions, the pupil distance measurement has to be 100% accurate. By reglazing your own frame, we are eliminating any potential measurement errors. We measure your pupil distance on your existing lenses by using a focimeter. With your higher prescription, your existing lenses should also have a fitting height measurement (the same as you would if your frame had varifocal lenses), and we then use these measurements when making your new lenses.

If we supplied a new frame, even if you measure your pupil distance yourself, or we measured it from one of your old frames, we would not have the fitting measurement for the new frame as fitting heights vary depending on the shape of the frame.

We don’t just want to provide you with cheaper, more affordable high index double aspheric lenses, we obviously want you to be able to see!


Why can’t I just take a photo for you to take the measurements and transfer the fitting heights to a different frame, the same as you do with varifocal glazing?

We can take pupil distance and fitting height measurements from a photograph for lower strength and less complex prescriptions. We also do this for varifocal lenses.

The issue with doing it like this with very high power lenses is that with increased lens power comes a lesser margin for error in terms of optical tolerance.

With a +1.00 lens you can be 3mm out in either direction when measuring a pupil distance measurement and it will still fall within British Standards for Spectacle Lenses. The wearer will not notice any difference and the lenses will pass final inspection as it only creates 0.6D of prism across both lenses. If you moved a pair of +10.00 lenses by 3mm each, you would create 6.0D of prism across the pair. To pass inpection, you are allowed up to 0.67D. Even if the PD was 1mm out on a +10.00, that still puts 1.0D of unwanted prism on the lens and they would fail inspection.

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  • 5 star review  Amazing service and all dealt with quickly and professionally. Also very friendly! I was struggling to get my favourite glasses fixed and Simplespex had no problem at all. The price was so reasonable and it was all dealt with super quick and super smoothly. I would very highly recommend.

    thumb Lynne Arnold
    October 13, 2020

    5 star review  I have sent my Silhouette glasses for repairs to Simplespex a few times over the past 5-6 years. I have always received prompt and excellent service at a very reasonable price. I recommend them highly.

    thumb Priyadarshini Raykar
    March 15, 2021

    5 star review  I have placed orders with this company on several occasions over the past four years. The service I have received has been wonderful. Always going that extra mile to make sure my order is correct. The quality of the glasses couldn’t be better. A fraction of the cost of high street opticians. It’s worth just getting a prescription and passing it to Simplespex to make your glasses. I have recommended them to many of my friends. I would highly recommend Simplespex to anyone needing glasses.

    thumb Tony Bryant
    April 30, 2021
  • 5 star review  Brilliant service - genuine parts and great value. Would definitely recommend

    thumb Greg Scott
    August 10, 2020

    5 star review  After having reservations of buying lenses online, and finding most of them that only offer their own lenses, no guarantee and fancy marketing, I found Simplespex. Its rare these days to find people who genuinely know what they are talking about and are passionate about the service they offer and the quality of the products they sell. I was amazed by their knowledge, quality, price and turnaround. Will use again without hesitation.

    thumb jbry83
    September 26, 2020

    5 star review  I had a problem with the hinge mechanism on my glasses so phoned George who recommended that I send photos. He called back to discuss the issue and felt is was fixable so I sent the glasses. The repair was excellent, the glasses were returned quickly and all for a total of £25 well spent, including return postage. Thanks so much George and your team. You deserve every success for your top quality service at very reasonable cost. Specsavers had declared my glasses u/s so I had almost given up but they are now more or less back to new.

    thumb clive chafer
    July 20, 2020
  • 5 star review  Fast Service Great repair to a hinge on my friend expensive sun glasses

    thumb Bob Fernandes
    September 11, 2020

    5 star review  Excellent service. Rapid (48hr ) turn around as promised. Repaired arm of Silhouette spectacles a perfect match. Thank you!

    thumb Peter West
    August 11, 2020

    5 star review  So happy to be able to wear my glasses again, great job! Cannot even see where the fix was done on my broken frames. Well worth it, very happy with the repair job.

    thumb Govi Rai
    October 24, 2020