Conventional glasses dispensed by the few optometrists to practice in the developing world are beyond the reach of all but the wealthiest of people
Or approximately 10% of populations. In answer to this problem, aid organizations are employing four alternative corrective eyewear distribution models helping impoverished vision impaired people in need:
- Recycled glasses
- Ready-made glasses
- Snap-in lens glasses
- Self adjusting glasses
The most common model. Donated glasses are collected, in some cases refurbished, then distributed to vision impaired people. Eyesight is first assessed and then people are offered a choice of glasses in differing frame sizes that best match their degree of refractive error.
Usually ordered and manufactured in large volumes to allow for wholesale pricing, these glasses come in one or more plastic unisex frames with preinstalled prescriptive lenses correcting refractive error in uniform gradations of half-diopter strengths. Lenses are identical left to right and, like recycled glasses, do not always match exact vision requirements. Ready-made glasses may be ordered to correct both hyperopia (near vision problems) and myopia (distance vision problems).
Snap-in lens glasses
This model allows allows the assembly of prescriptive eyewear on the spot, with pre-manufactured snap-in lenses of varying strengths matched to a selection of frames. Eyesight is assessed to determine a refractive error prescription, and lenses providing a best possible match are inserted into place.
Self adjusting glasses
Also called self adjustable or adaptive lens glasses. Recent innovations in optometric technology allow wearers to actually participate in the process of correcting their own refractive error by adjusting the lenses to suit the vision requirements of each eye. Priced at under $20 a pair, two models are currently in use, each of which may be distributed by non professionals (people with no optometric training) and require no specialized equipment to dispense. Self adjusting glasses