1 Ask yourself: what do we exactly mean by individualised lenses?
In practice, dispensing opticians often use the words tailor-made, personalised and bespoke in our lens explanations. Individualised lenses often use the latest freeform technology, which takes into account the spectacles’ vertex distance (VD), face form angle (FFA) and pantascopic (P). Due to a surfacing and polishing process, the wearer will experience enhanced visual performance through the calculated compensated powers.
2 Understand the individualised measurements required and their importance.
For prescriptions +/- 5.00D or above, it is best practice to perform the effectivity calculation should we establish a difference between the testing VD and the VD of the chosen frame. This will ensure that the patient is not over or under corrected while wearing the new pair of spectacles. The pantascopic angle must be measured after the frame has been perfectly fitted to the patient in order to ensure the patient is looking through the correct visual axis.
In progressive powered lenses (PPL), this will affect the positioning of each zone as well as the surface aberrational astigmatism (SAA) distribution. The FFA affects the spectacle magnification by adjusting the shape factor. This therefore alters the wearer’s depth perception as different retinal image sizes are produced. The accuracy when taking these measurements is vital, hence lens suppliers’ investment in the latest technology to aid with dispensing measurements.
3 Make excellent use of the most modern and advanced technology available.
Different lens suppliers have advanced measuring tools/software to further personalise these lenses. Essilor recommends using its Visioffice system, which tracks the patient’s eye movements, eye dominance, head movements and general posture. A personal eye code is produced capturing all the measurements and used to order the lenses. Hoya offers its Visureal Master whereby the patient looks at the mirror while standing in their most natural posture. The mirror contains six cameras. An image is taken using two cameras best suited to the patient’s height and face/frame type. The dispensing optician can run related software to further tailor the lenses exclusively to the patient’s lifestyle and occupational needs. A unique code is generated for each pair of spectacles ordered. In both occasions, the patient will feel looked after and enjoy a personalised experience that will set you apart from the crowd.
4 Explain in layman terms what individualised lenses mean for the patient.
Mould your explanation to each wearer and their needs. Don’t confuse the majority of patients with the extensive technical aspects of lens manufacturing. However, we know that most mathematicians and engineers will not be satisfied with: ‘these lenses will give you better vision.’ After all, they know it all. Try explaining the exact differences from one lens design to another and how this will impact their lifestyle on a daily basis. Is it a wider reading area they will benefit from? Is it the enlarged width of the corridor that will help with their screen use at work? Or is it the wider distance zone that will improve the comfort while driving on their daily commute?
5 Ask the patient specific questions; what lenses have they worn before?
Making the lenses individual to the wearer means gaining full understanding of the wearer’s visual habits, body posture, hobbies and occupational needs. For PPL patients, use open questions to help you decide what PPL design and positioning will be best suited to their individual needs. One size does not fit all. One important question to consider is what type of lenses have they worn before and how easily they can tolerate change. Individualised lenses can produce amazing results, however, you may find that some patients have difficulty adapting to the compensated powers. Another important aspect to consider is the frame fitting and the wearer’s habits. Each frame must be fitted before any measurements are taken. The wearer’s habits must be taken into account when adjusting the frame, such as their most natural positioning on the nose bridge. While taking all measurements, ask the patient to mimic their most natural posture, ie their desk posture when dispensing occupational lenses. If this is not considered and the user wears the frame much lower post collection, the purpose of individualised lenses will be defeated.
6 You are the most advanced software in practice.
Despite all the fancy yet revolutionary gadgets we have available at our finger tips, the most powerful tools dispensing opticians have are their PD ruler in conjunction with their knowledge. My personal experience has taught me that relying on technology can lead to real life scenarios where patients are complaining of ‘something not being quite right’ and I find out that their lenses have been ordered using -3mm VD. I am certainly pro using technology to be more efficient in practice, but the most advanced computer we have is our intellect. It is our duty and care to analyse the patient’s visual needs using all our dispensing knowledge as well as all available technology.
7 Stay up to date with the latest lens technology.
Never stop learning and be open-minded. Attend as many CET events as possible to remain up to date with new equipment developments that can aid you to be better.
- Suzana Gorda is a dispensing optician at an independent practice.