Nearsighted and farsighted

The price we pay for want of eyeglasses is steep: $269 billion a year. That number, published in a 2009 WHO-affiliated study, is an estimate of worldwide lost productivity due to refractory error--a kind of vision problem, like nearsightedness, that glasses can fix. But, though eye exams and eyeglasses don't cost much, they require lens-grinding equipment, an optometrist, and a machine into which to trustingly settle the chin. All of those are in short supply in many countries. Who's tackling cheap vision correction?

Gadgeteers, it turns out, are drawn to eyeglasses just as they are to cookstoves. The holy grail of low-resource eyeglasses are the kind you just hand to a person--he puts them on, adjusts them, and sees. Such glasses exist. The New York Times wrote recently about high-tech eyeglasses that allow untrained wearers set the focus themselves, some using a sliding-lens system and others an injectable liquid. The companies developing this technology, which include AdSpecs in England and Focusspecs and U-Specs in the Netherlands, plan to drive down production costs and send millions of eyeglasses to poor countries, thereby helping many of the 145 million people who have bad vision from uncorrected refractive errors (but not with astigmatism--those people still need optometrists). The website of an organization affiliated with AdSpecs, Centre for Vision in the Developing World, explains how the glasses work; it's well done and worth a visit.

But as a former U-Specs executive pointed out in the Times article, the real cost is not in the nifty glasses themselves, which will be a few dollars or less once economies of scale are in place, but in their distribution. After all, many donated pairs of eyeglasses already make their way to poor countries through organizations like New Eyes for the Needy. That group claims to distribute hundreds of thousands of pairs each year, a number that dwarfs what the gadgeteers have yet accomplished--and demonstrates that powerful built-in networks for distributing glasses already exist. Are all these parties talking to each other?

Similarly, Vision 2020, the cleverly-named partnership between the WHO and the International Agency for the Prevention of Blindness, is tackling all forms of avoidable blindness, with an emphasis on developing better infrastructure rather than passing out post-optometry eyeglasses. As with so many low-resource problems, solutions to preventable blindness are many and partial. The best one may remain to be seen.

Stoves and disease

A blessing of modern life that feels decidedly mixed is the need to accept that seemingly pleasant old-fashioned ways are untenable and even dangerous.  Tiresome safety-conscious reformers have long had a way of pointing out that, say, the elegant horse and carriage brings with it piles of horse shit; the classic car's glossy dashboards are blindingly so; and the delicious all-American meal of burger, fries, and pop has abhorrent ingredients. You'd almost rather not know, but there it is.

So, too, I'm sorry to say, must go the open fire, with its beauty, its simplicity, its utility, its potent symbolism, and its many chemicals and particulates that lead to childhood pneumonia and a host of other diseases, both respiratory and otherwise.* I'm stretching the analogy, of course: a fire for s'mores is worlds apart from a fire for flatbreads.

Built fires are, in fact, a scourge. People suffer and die prematurely, as do forests and ecosystems and the climate, when fire is used for everyday cooking and warmth. In a recent New Yorker article (available by subscription only, alas) "Hearth Surgery," Burkhard Bilger describes it thus: "Clean air...contains less than fifteen micrograms of fine particles per cubic metre. Five times that amount will set off a smoke alarm. Three hundred times as much--roughly what an open fire produces--will slowly kill you. Wood smoke, as sweet as it smells, is a caustic swirl of chemical agents, including benzene, butadiene, styrene, formaldehyde, dioxin, and methylene chloride....Indoor smoke kills a million and a half people annually." Not to mention heats the atmosphere with terrible efficacy.

Seems like a low-hanging fruit, no? Get people cheap, powerful, clean stoves; prevent suffering, deforestation, and global warming. But it turns out that designing and introducing good cookstoves present knotty engineering and cultural problems. As Bilger explains, it's hard to come up with a stove that's simultaneously efficient, cheap, clean, durable, and easy to use. And many people accustomed to their usual way of cooking aren't eager to change. (As the New York Times put it in a recent article, can you imagine asking a traditional Italian cook to make risotto in a microwave?)

But stove development is hot. It has attracted organizations and passionate hobbyists who like the technical challenge and the idea of saving lives and the planet. To learn more, check out the blog Improved Biomass Stoves for discussions of stoves and stovers (as developers of stoves often call themselves). BioEnergy Lists and Rocket Stoves are resource sites for stove developers. The journal Indoor Air reports on these issues (free access to developing-world institutions). Then, too, there are GTZ; Stove Camp; ETHOS; Darfur Cookstoves; and the Ashden Awards, among many other sites. Lists of relevant links much more comprehensive than mine can be found here and here.

Let's hope that good stoves spread everywhere and make open fires a matter of misguided nostalgia.


*Carbon monoxide poisoning, pneumonia, lung cancer, bronchitis, chronic obstructive pulmonary disease, heart disease, high blood pressure, low birth weight, cataracts...

Ultrasound in Rwanda

Ultrasound is something I've blogged about before--I'm excited about an inexpensive pocket-sized version. Something like that may be what replaces the stethoscope in the near future, and American medical students and residents are already being urged to make it part of their armamentarium--though takeup is still not as good as it could be. My father frequently laments the difficulty of getting his residents to look for pleural effusions at the bedside, and very few ER physicians routinely do an ultrasound of the heart to determine if an elderly patient with low blood pressure is suffering from a weak pump or a dry one.

But as helpful as ultrasound will eventually prove in wealthy settings, it could be revolutionary in low-resource clinics. Paul Farmer's NGO Partners in Health studied ultrasound in Rwanda, training local physicians in its use. They found that the scans were accurate and sustainable: the Rwandans' and the American trainers' image interpretations agreed 96% of the time, and the clinic continued to scan avidly after the Americans had left. It was found to be particularly beneficial in planning surgeries and in caring for pregnant women.

Every low-resource clinic should have at least one ultrasound machine. The trouble is that the damn things are expensive--but there are a lot of older-generation models lying around the US, and getting those to where there are none would be a good start. Thomas Jefferson University has an equipment donation program, as does the World Federation for Ultrasound in Medicine and Biology.

Gadgets in the field: Cell-phone microscope

The cell-phone microscope appeared recently in the New York Times. It costs a few dollars, hooks onto a cell phone, and allows to examine blood samples microscopically. A version called the Cellophone and created by Aydogan Ozcan's group at UCLA creates digital holograms of the cells and allows for mathematical analysis of the image. (Ozcan has created a fledgling company called Microskia to develop the idea.) A related invention out of Berkeley is Daniel Fletcher's CellScope.

Wow. Here's a reason to be thankful that cell phones blanket the earth. If cell-phone microscopes can replace the full-sized version even for limited applications like malaria screening, they could be immensely helpful.

When will these devices be ready for marketing and distribution where they're needed most? Who's going to buy them up and send them into action?