Over the past 18 months I have been reading up in my personal time on water, its availability, requirements, usage and distribution. I believe it to be a particularly important problem for systems engineers to examine, since it needs to combine aspects of purification technology with energy analysis, human practices, policy and politics, and one which I believe mainstream media does not report on as much as it perhaps should.
I was therefore happy to read a well-written BBC article by Richard Black that describes the problem and complexity of modeling water as a resource. If you’ve been trained in chemical engineering or systems engineering, the material is probably not new to you, but it’s presented very well.
The glasses work on the principle that the more liquid pumped into a thin sac in the plastic lenses, the stronger the correction.
[Joshua Silver] has attached plastic syringes filled with silicone oil on each bow of the glasses; the wearer adds or subtracts the clear liquid with a little dial on the pump until the focus is right. After that adjustment, the syringes are removed and the “adaptive glasses” are ready to go.
Currently, Silver said, a pair costs about $19, but his hope is to cut that to a few dollars.
This is interesting for several reasons:
It increases the flexibility of a single pair of eyeglasses for different situations.
It allows the entire field of view to be the same focal length, unlike a bifocal or multifocal lens that has only a small region at the required focus and everything else off-focus.
It decreases the long-term cost by allowing eyeglasses to adapt to changing eye-lens powers over many years (assuming the glasses last that long).
It’s a clever emulation of what nature does for the eye-lenses of most species: make them fluid-filled and change their shape with muscle tension.
Overall, seems like a design that solves several problems simultaneously. Quite impressive.