What is presbyopia and what are the symptoms?
Presbyopia is natural ageing of the crystalline lens which scleroses and loses its elasticity. It is characterised by difficulties with near vision (reading, close work). It affects everyone over the age of forty. Worldwide it is estimated that over 1 billion, 300 million people are affected by presbyopia. In Sub-Saharan Africa is occurs early, at around the age of 39.
Ways and means of combating the problem
There are several types of optical correction available to compensate for the phenomenon:
- Single focus lenses for near vision
- Bifocal lens
- Tri Trifocal lenses
- Progressive lenses.
Optician’s training and practice
Access to this correction is subject to holding a prescription obtained after a visual examination carried out by a vision specialist (ophthalmologist/ optometrist).
Most opticians are established in the capital cities of our countries (Abidjan, Dakar, Nairobi, Conakry, Abuja, Accra, Johannesburg) and in some other major cities (Lagos, San Pedro, Port Gentil, Pointe Noire). Most of those in French-speaking countries have been trained abroad; this is also the case for some opticians in English-speaking countries (Uganda, Liberia) since there are no training structures available in their own countries.
Ophthalmologists and optometrists are also established in major towns and cities. Patients with presbyopia, after being examined, go to see their optician, who sells the various corrections available.
Progressive lenses are the “preferred lenses” amongst the so-called privileged classes.
Patients from the privileged socioeconomic class purchase progressive or bifocal lenses.
Nowadays appearance, ease of use and visual comfort at all distances mean that progressive lenses are the favoured lenses used by the privileged and middle classes.
Mineral or organic lenses, personalised or in small frames, grey or brown photochromic, with or without anti-reflection, scratch- and dirt-resistant treatment, the customer has no hesitation in paying for these lenses, as long as they give him good vision.
Old statistics from the Wossinu Quacoe Ophthalmic Optics Office in Lomé, Togo covering the 12 months of 1982 showed that:
- Progressive lenses represented 0.42% of lenses worn by presbyopes
- Bifocals: 68.97%
- Lenses for near vision: 30.61%
On the other hand statistics for 2007 showed the reality of just how far progressive lenses had penetrated into the market amongst the middle and privileged classes. This is demonstrated by the fact that amongst customers wearing spectacles in 2007 figures were:
- 83.77% wearing progressive lenses
- 14.66% wearing bifocals
- and only 1.57% wearing lenses for near vision.
In just 25 years, between 1982 and 2007, the wearing of progressive lenses increased by 199%.
Nevertheless there are solutions open to people in underprivileged situations.
Presbyopic patients adapt to their situation, firstly by holding the text they are reading at a distance or drawing back from any close-up work.
- A tailor suffering from presbyopia has to be able to continue to sew. He often has apprentice tailors working with him who are younger than him and still enjoy complete accommodation. So the young apprentices help their boss in taking measurements, reading and also in with drawing and cutting out “patterns”. When a presbyopic tailor is working alone he turns up the lighting to improve the luminosity and vision of his work surface.
- Similarly a lady working on a market stall confided that since she has problems with near vision she has got used to threading her needle in the morning, before going to market, to avoid having problems at the end of the day when she returns home and has to mend her children’s clothing.
The expansion or increase in travelling salesmen selling spectacles
For those less well off financially, but for whom good near vision is absolutely essential to their everyday work, there are lots of traveling salesmen doing well out of selling spectacles on the markets.
Others set up on the roadside to attract customers.
Some have market stalls where spectacles are just one of the items on sale.
They mostly sell near vision spectacles but sometimes it is possible to find bifocals too, with neutral long vision.
What is the procedure used?
The patient goes to the stall and tries spectacles on until he finds lenses that enable him to see letters bigger.
Some religious charities also come to the help of those in need. They receive donations of used spectacles and distribute them, using the same procedure.
In view of the poverty of some populations, various development partners, Sight Savers International (SSI), the Swiss Red Cross (CRS) and Christoffel Blinden Mission (CBM), have set up decentralised structures for screening and performing visual examinations and, depending on the case, mounting spectacles and selling pre-assembled spectacles at reasonable prices.
As for the extremely poor, they have absolutely no hope of purchasing lenses since they have other priorities facing them.
As they say “presbyopia won’t kill us so the spectacles can wait!”
Developed countries that are able to choose between bifocals, lenses for near vision and progressive lenses, with or without surface treatments and, more recently, personalised lenses, don’t know their luck! They see it as something normal and natural whereas today 70% of the population in developing countries living in rural communities would see this as something of a miracle; their survival is based on resourcefulness and making do.