To complement our CET module on occupational lens dispensing (page 25), Peter Sanders offers some practical considerations on enhanced reading and occupational lenses
I recently came to the conclusion that most dispensers do not understand the enhanced reading lens and if they do, they are not sure which one to use.
I would like to dispel the myth that the lenses are just for computer users. They are suitable for all presbyopes. In the literature they put out, most suppliers clearly point out that the lens gives the presbyope greater near-vision scope. Quite often they show the near vision achieved with standard reading lenses compared to that of enhanced readers.
Now let us assume you offer them to all presbyopes. How do you decide which one to use when you consider that 13 companies offer 30 variations of the lens, some offering greater scope than others?
There are several distinct near-vision requirements. Although early presbyopes still have plenty of accommodation, they can benefit from the enhanced reader because they can wear them like a conventional progressive and it gives a good introduction to them.
Generally, the low degressions of -0.75 work well for the early presbyope. Providing the add is low, about +1.00 to +1.25, then most of the lenses with a -0.75 would be tolerated. Sola Access, Norville Continuum and Hoya AddPower are quite convenient lenses as they are fitted on the HCL so the only measurement required is the PD.
DISPENSING FOR THE OFFICE
The office worker is the most obvious beneficiary of the enhanced reader, but still only a small proportion of presbyopic office workers are supplied with these lenses. By providing them, you are not only improving their vision, but also their posture in front of the VDU screens. In general, the most successfully enhanced reading dispense is when the regression given is 0.50D less than the add - for example, if the add is +1.75, give a degression of -1.25. This will blur the distance vision by 0.50D, giving the wearer clear distance vision of about 2m away. This is sufficient for most office tasks without having to change spectacles. In general, the longer-regression lenses tend to be more comfortable to wear. Like any progressive the longer the progression zone the softer the change. This has to be balanced with where the patient wants the majority of their vision. 
Let me explain. Someone whose job is mainly data input requires a large inter section and less close near vision (this does not mean the near vision is reduced, in fact it will still be much larger than any conventional progressive lens). In this case, a longer degression zone would be better. An executive whose main requirement is reading, with very occasional screen use, would benefit more from the shorter regression zone.
On the other hand, if he has to attend board meetings he may require a longer degression zone. In general, people who use laptops prefer the shorter degression zones, sometimes set a bit higher than recommended.
The InterView -0.80 can be successfully dispensed into a half-eye frame. If you decide to do this, it is obvious you cannot set the heights as recommended by Essilor, as quite often the frame sits too low. In this case it usually works if the centres are set fairly high in the frame, sometimes up to three quarters of the way up. I have done this in a Savile Row Executive (old 722 half-eye). Those aware of this frame know that it sits fairly low on most people and it worked well in this case with the centres set at about 4mm above HCL.
When using these lenses, make sure you dispense within the manufacturers' recommendations. Shamir Office has a minimum fitting height of 16mm from the bottom rim and 13mm from the top rim to get full benefit from the lens. Therefore, sometimes you may need to modify your measurements when ordering the lenses. The measurements are not as critical as they are for most progressives. Sometimes you may need to increase the heights to get the full reading comfort. This may mean setting the lenses above pupil centres in some cases but, in general, it works. Sometimes you may lose some of the intermediate vision with modern frames if there is not enough height in the frame. If this is the case you can go for a higher degression as you will lose some of it at the top. On the other hand, you may feel the patient does not require the full degression that the lens can offer.
A vast range of occupations would benefit from these lenses. Some people, such as lecturers, teachers and doctors, will benefit from occupational lenses that offer full distance vision as well as the large intermediate and reading potential.
Many people do not require much near vision at work and mainly use their specs for reading newspapers and magazines. They often buy off-the-shelf ready-made readers. Enhanced reading lenses will give them greater comfort of vision and help differentiate what we supply from ready-made readers.
THE LENS TO FIT THE JOB
There are many occupations where enhanced reading lenses are beneficial and our job is to establish which is most suitable depending on the Rx and the job.
Recently I spoke to a plumber who had been supplied with a pair of progressives and a pair of readers. His main complaint was that he could not see comfortably with either. The enhanced reader would resolve his problem, so we must ask the appropriate questions, listen to the answers and advise accordingly.
The retired elderly find these lenses of benefit as they have no accommodation. While most do not use computers, this should not stop you dispensing these lenses. Lots of the elderly need spectacles to see what they are eating and these lenses help tremendously. Playing cards, reading a newspaper, the examples can go on. Which lens you supply varies according to each individual's requirements. Many only want a deeper field of focus, in which case a smaller degression will do the job. For example, someone with a +2.50 add would find a degression of -1.25 fills their requirements, but in this case a longer degression zone would be more comfortable.
Only by dispensing these lenses do you get a feel for them. You are bound to get a few non-tols, but don't let that put you off. The more you dispense, the better you will understand them. It is easy to sell a pair of reading spectacles but requires more skill to dispense a pair of enhanced readers. Are we just salesmen or are we dispensers as well?
Turn to page 20 for a listing of the specification of lenses available in the UK