How Glasses Are Measured

Our highly tailored and personal approach to measuring ensures optimum vision.

If you are buying prescription glasses online or perhaps purchasing prescription spectacles in a store without having an eye examination first, you are typically required to provide just one measurement for your prescription lenses: the pupillary distance measurement or PD. This is the measurement of the distance between your pupils.

It is quite difficult to obtain optimal vision with glasses that have been made using solely the PD.

The back vertex distance (BVD) measures the distance from the front surface of your eye to the lens. This measurement is also very important for ensuring optimal vision. A pupillary distance measurement doesn’t take the dimensions of the frames into account or the tilt of the lens within the frame. Finally, we also need to take any curvature that is required on the lenses to maintain the shape of the frame into consideration as well.

The extra measurements we take ensure the lenses we fit are perfectly tailored for your exact requirements. We also look at the history of your spectacle lenses to ensure we have all the necessary information to ensure success with your new lenses.

We are in the envious position of having our own workshop in the basement of the store where we shape and fit lenses for our customers. By glazing the frames ourselves, we are in complete control. Your lenses will always fit your frames perfectly and the positioning of those lenses will be spot on.

We have built longstanding relationships with the leading independent lens manufacturers who only supply the most technically advanced lenses on the market. For patients with a high prescription, we are able undertake approximate calculations to check the cosmetic fit of lenses in frames. It may be that we opt for a different frame if the lenses are too visible.

We are also able to customise frames for our patients. With many of our frames, we can customise frames in terms of colour and material but we can also sometimes customise the frame size. You may need longer temples or perhaps a narrower or wider bridge. Having a frame made to your exact specification can ensure great comfort as well as stability.

Our highly skilled dispensing opticians can help too if you have a complicated prescription. They can help deliver the best cosmetic outcome of your spectacles, ensuring the lenses you require are suitable for a specific frame.


In our opinion, you know you have the right frames when you put your glasses on in the morning and don’t think about them for the rest of the day. This is our aim for all of our dispenses. We believe our very tailored and personal approach ensures the best visual experience possible, giving our patients the optimum field of vision.