This is fantastic. I love this kind of low cost, thoughtful technology. See:
http://www.adaptive-eyecare.com/index.htm
http://www.washingtonpost.com/wp-dyn/content/article/2009/01/08/AR2009010803492.html
QUOTES
". . . The approach of Adaptive Eyecare has been to develop a
completely new ophthalmic lens technology which permits us to
manufacture revolutionary new spectacles which are universal, in the
sense that one pair may be used to correct the vision of over 90% of
people requiring correction. The special feature is that the wearer
can adjust the power of each lens to his or her own requirements -
this is particularly useful for developing world populations in areas
which do not have adequate numbers of those specially trained
personnel normally associated with the provision of vision correction.
The lenses in Adaptive Eyecare's spectacles operate in a manner which
is somewhat similar in its optical function to the crystalline lens
in the human eye - our lenses have the feature that the curvature of
the lens surfaces is under the control of the wearer of the
spectacles, and a simple manual adjustment is all that is needed to
vary the power of each lens. In use, the wearer adjusts each lens so
as to get clearest vision. This process takes less than a minute for
both eyes. Having found the best setting, the lenses are then set,
and the ancillary device used for lens adjustment is removed and discarded.
Adaptive Eyecare's adaptive lenses are fluid-filled and the power is
changed by varying the amount of fluid in the lens. The power range
of our lenses is +6 to -6 Dioptres, and the optical quality is
similar to that of the typical human eye."
- Jed
