SAUL GRIFFITH REMEMBERS THE EXACT MOMENT WHEN he was inspired. He was in Africa, participating in a Lions Club program to recycle used eyeglasses by giving them to impoverished rural Africans. “It’s not a very good way to correct vision problems, but it’s a lot better than nothing,” he says. He wanted especially to help a four-year-old boy with such poor vision he had never been able to read or play ball with his friends. So Griffith and his colleagues took the thick lenses from a pair of adult glasses and fitted them into child-size frames.

“I remember putting them on him … and the smile as he saw the world clearly for the first time. Immediately he ran out and started to play soccer with his friends. It was a marvelous experience.” That prompted Griffith to find out why glasses couldn’t be made cheaply enough for residents of the Third World. He discovered that frames can be made affordably and prescriptions can be determined cheaply too. The problem is the equipment needed to mold simple plastic lenses. It costs hundreds of thousands of dollars, takes up a lot of space, and can be operated only by highly skilled technicians.

Or rather, that used to be the case. Griffith, who is earning his doctorate at the Massachusetts Institute of Technology, invented a completely new way to produce eyeglass lenses. His invention is small enough to fit in a suitcase, requires very little skill to operate, and can be produced inexpensively. There’s reason to hope the apparatus will make it finally possible to provide basic vision care for the world’s poorest people. According to the World Health Organization, at least 150 million people with severe visual impairments have no access to eyeglasses. The United Nations estimates the number of people who need glasses but can’t afford them at as high as a billion.

The power of technology to make the world a better place was seen again and again at the National Inventors Hall of Fame’s thirteenth annual Collegiate Inventors Competition. Twenty finalists from around the world met in New York City on November 12, 2002, for a final round of judging that selected six grand-prize winners, who were announced on November 14. Each winner received a $20,000 award, $2,000 worth of computer equipment from Hewlett-Packard (a sponsor), a set of tires from the Goodyear Tire & Rubber Company (another sponsor), and a medal commissioned by the Hall of Fame. And each winning student’s adviser received $10,000 in recognition of his or her contribution as a mentor.

The competition is a search for young inventors just embarking on their careers who have already demonstrated exceptional inventive skill. Although there’s no way to know which of the finalists will make it into the history books, one thing that’s certain is that all the grand-prize winners have started their careers most impressively.

Consider Lei Wang, a postdoctoral researcher at the University of California at Berkeley. The invention that won Wang his place among the grand-prize winners is a revolutionary technique for grafting a new amino acid into the genetic machinery of a cell. Only 20 types of amino acid are used in cells in nature, and scientists have looked for years for ways to introduce new varieties. Wang figured out a way to get a twenty-first type of amino acid into an E. coli bacterium. To demonstrate that this wasn’t a fluke, he and other researchers at Berkeley have repeated the process with 15 other amino acids. He believes that pharmaceutical companies will be able to use the technology to re-engineer cells to produce new classes of drugs.

Yu Huang, who is pursuing her doctorate in chemistry at Harvard University, won for an invention that has already attracted international attention. In a remarkable breakthrough, she developed a robust new process for manipulating materials on the molecular level, then used her process to manufacture nanoscale computer circuits capable of performing arithmetic calculations. Her invention allows researchers to take molecular transistors and assemble them on a silicon surface with “wires” of the carbon molecules called nanotubes. The resulting nanoscale circuits can be made to behave exactly like circuits in conventional microprocessors, suggesting that they may provide the basis for a powerful new realm of electronics.

Zachary Knight, a doctoral student at the University of California at San Francisco, won for an invention expected to play an important role in the emerging field of proteinomics, the study of genetic proteins. In the effort to map the human genome, researchers have recognized that much of the complexity of life is written not in DNA itself but in the proteins that DNA produces. Scientists are just beginning to find ways to examine those proteins in detail, and Knight has given them a powerful tool. He uses a technique called phosphorylation mapping to scan proteins’ structure, quickly providing a much more detailed look than conventional techniques give. He’s now developing ways to make his technology available to other researchers, and he expects them to find applications that range from identifying tumors to determining genetic predispositions to disease.

Jeffrey Anker, a doctoral student in physics, won for an invention he calls “MagMOONs,” meaning magnetically modulated optical nanoprobes. If you think that sounds like a gadget from a science fiction movie, you’re just about right. Anker’s MagMOONs are extremely small magnetic particles that are dark on one side and light on the other from a coating of materials used to conduct chemical assays. For years chemists and biologists have conducted assays with fluorescent materials that are easy to spot in a microscope; Anker’s MagMOONs permit much more precise assays because he can use a rotating magnetic field to make the particles oscillate, so that they appear to blink on and off. These advanced assay tests are expected to find their widest use in biomédical research, but the first interest in the technology has come from the Defense Advanced Research Projects Agency.

One inventor seemed to receive an especial lot of attention at the awards ceremony. Carlo Giovanni Traverse, a postdoctoral researcher at Johns Hopkins University, has invented a noninvasive test for colorectal cancer. His technique looks for traces of DNA shed into the stool by cancer cells. He has licensed the technology to a firm called Exact Sciences Corporation, which hopes to market test kits.

The reason Traverso’s invention got such a response is that it has the potential to eliminate the need for many colonoscopies, which are currently the best way to find evidence of colorectal cancer. Nick Clooney, the TV personality who presided over the awards ceremony, wondered aloud whether Traverso could arrange for the invention to be available before his own next exam.

Traverso says he heard similar comments throughout the competition and that he gets them from friends and acquaintances too. “I don’t know whether to say this is fortunate or unfortunate, but people want to give me their stool samples,” he says. “Maybe on a social level that’s not the best thing to happen.”