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Changes
So why did it take so long and what has been learned about the products we have to choose from currently in relation to those on offer only three to four years ago? Phil Gilbert explains: 'Firstly and probably most importantly we have seen an overall increase in lens entries within the publication of over 38 per cent. In 2009 there were 957 individual lens entries in comparison to 1,326 for 2012, the vast majority of these representing the manufacturing swing away from semi-finished progressive lens production in favour of freeform production.
'In fact the number of traditional semi-finished progressive lens entries has reduced by 25 per cent, indicating the decline in this technology, whereas there has been an increase in plastic freeform progressive technology of 662 per cent, a massive movement from 53 entries up to 351.
'Manufacturers such as Zeiss and Rodenstock no longer offer any semi-finished plastic progressive lenses and BBGR, Essilor, Nikon and Seiko only offer one semi-finished product, the rest being freeform, an indication of how this technology is now playing such an important role in optics.
Freeform is also playing its part in both single-vision and occupational lenses with an increase from eight to 98 entries in single vision and from 0 to 25 entries in occupational progressives. There are even a few freeform versions of degressive lenses, bifocals and progressive glass lenses and I am sure these numbers will rise in the future.
'Another area of definite growth is in the lifestyle sector which encompasses lens products designed for outdoor activities where both the style of the frame and the tint are taken into account. There is a definite increase in higher base curve lens entries and although there were a few lenses of this type available in 2009 they had been included in the general lens sections. Now, with so many higher base curve lifestyle lenses available, together with specialised sports tint options, they do warrant a separate section of their own.'
Traditional lenses
But it is not all change, as Gilbert explains: 'Looking at traditional lens products such as single vision, bifocals and trifocals the number of entries is fairly equal to the previous issue and surprisingly there is no real decline in the number and variety of the older style products on offer. This is also true with regard to specialist lenses such as lenticulars.
Another fact concerns the range of glass lenses available. The number of glass products on offer has also remained flat but they still represent a surprising 11 per cent of the overall number of available lens options.
'It must be remembered that the figures quoted above indicate the physical number of individual lens entries in the publication and one lens design can feature many times in the Availability Index if you take into account all the different refractive indices and treatments such as photochromic and polarised versions on offer.'
Table 1 shows a generalised picture of the product-type movements from 2009 to 2012 and the new production trends can easily be seen.
Despite the significant workload, Gilbert describes his updating of the book as a fascinating journey. 'We have waded through the "marketing speak" and avoided the smoke and mirrors in order to hopefully produce optical facts. On the way we have discovered many new products which can give every practitioner new direction and access to many future dispensing opportunities.'
No practice, glazing laboratory or optical representative should be without a copy and it is definitely time to ditch that old version currently languishing in the drawer. ?
? Ophthalmic Lenses Availability by Phil and Pat Gilbert is published by the ABDO College, £45 plus £8 postage and packing, 331pp. To order, phone the ABDO Bookshop on 01227 733904 or order online at www.abdocollege.org.uk/bookshop.
? Phil Gilbert is a dispensing optician and a member of the Technical Committee TC172 for British Standards reporting to the Federation of Manufacturing Opticians. Pat Gilbert has 12 years' experience working for Zeiss
