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Johnson & Furze Opticians In Thornbury

7 Chapel Street

Thornbury, BS35 2BJ


More than an optical prescription

The lens power that gives the clearest vision when looking far away is found whenever your eyes are tested. This is the end of the matter for most opticians. Not with us. We don’t simply pass your data over to a lens company.

For us, this is just the start. The numbers are raw materials. To get the best performance they must be combined with what we know about you and how they will be positioned in front of the eyes. We have unique skills in doing this.

Lens Solution
Not just a brand

Not just a brand

No company has a monopoly on lens technology. Anyone can now buy equipment that is capable of making brilliant lenses, but more than 99% of lenses are made with the default design.

Standard lenses are based on a list of assumptions that are never all true for any one person.


Most people don't think to question: how far and at what angle the lens is mounted from the eye, the relative important of distance or near, or whether a person has a tendency to turn their head or turn their eyes when viewing to the side. We fiddle with the dials to get lenses that work for you.

Masters of the art of prescribing

Should the lens that gives the clearest vision during an eye test be prescribed?

If it were only that simple. The prescribing of lenses is as much an art as it is a science. Every change in focus affects the size and shape of imagery, and require recalibration of visual perception and eye movements. Like a medical prescription, the potential for good is always accompanied by the possibility of unwanted reactions.

There is no substitute for decades of experience with feedback. Testing lots of people is not enough if you never get to see them again. We benefit from continuity of care as much as our clients do. It is only by seeing people over the years that we learn what worked and what could be done better.

Lens solution for the clearest vision
Glasses Lens Solution

Crunching the numbers

An optical prescription only describes the focusing power through the very centre of the lens. How the rest of the lens performs is governed by lens design. There are competing trade-offs between various abberations and aesthetics, and the lens design that works best is as much judgement as it is maths.

Behind the scenes of how we design our lenses is not glamorous. There is no getting away from the numbers. Our lenses are designed with iterative numerical methods that enable optimised solutions considering tens of thousands of light rays passing through different parts of the lens based on a model that predicts lens distortions and eye rotations.

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