David Price, 46, can't remember a time when he wasn't interested in science. He was captivated as a child by the race to the moon, prompted in part by his father's career as an aeronautical engineer. Now a computer scientist who works on weather-prediction models at the National Oceanic and Atmospheric Administration (NOAA), Price says science and technology were always topics around his house growing up.
However, Price's early scientific ambitions didn't involve much computer programming. After earning an undergraduate degree in geology from Harvard University, he enrolled as a graduate student in structural geology at the University of Utah. While he was completing his studies, he lost most of his vision. Unable to do more fieldwork, he took a master's degree in geology then launched himself into a new field.
Before going to work for NOAA, Price worked on a big challenge in computer science: developing a prototype system that enables people to create computer programs using normal written English sentences. Recently, he described to Science Careers how his interests developed and how he found inspiration in the challenges posed by his disability.
D.P.: My grandfather was an economic geologist. Whenever he came out to visit our family, he would bring along interesting and beautiful rock specimens to show to my brothers and me. Even more important, when I was 7 or 8 years old, my family started taking weeklong backpacking trips. I remember, on many occasions, looking across at a mountain, ridgeline, or valley and wondering how it got there. It was this desire to learn how mountain ranges develop that led me into the field of regional structural geology and tectonics, which examines the geologic features of an area, such as how the rocks are faulted or folded, and tries to reconstruct its history -- how the mountains and valleys got to be there.
I loved being out in the mountains, hiking around and mapping the geology. I also loved solving the puzzles that structural geology focuses on, putting the pieces of a puzzle back together when you don't have most of the pieces.
D.P.: My vision problems first appeared when I was 11 years old. I had an optic nerve tumor in my left eye. At that time, the treatment was to remove the nerve and the tumor together; as a result, I lost the vision in my left eye when I was 12 years old.
The first symptom of a similar problem appeared on my right optic nerve when I was 16 years old. Fortunately, new treatment options permitted me to wait on treatment and see if symptoms progressed. The prognosis was for a gradual decline in vision and, when the amount of loss became significant, the tumor could be treated using radiation. That would stop the vision loss, and I would probably regain a little of what was previously lost.
Unfortunately, this isn't what happened. My vision loss proceeded slowly throughout high school and college, and I adapted to it without realizing it. In the spring of 1991, just before my fourth and final season of my graduate fieldwork, there was what you might call an eye-opening moment. I was visiting a neuro-ophthalmology specialist, and he asked me, "How do you walk down stairs?" Unlike most people, who can track the top step in a flight of stairs in their peripheral vision and approach and start down without problem, I had to always look down to find the top step before I could proceed down. This conversation made me realize that I had to look down to place my feet while hiking out in the field, greatly slowing down my progress and making fieldwork more dangerous.
Then, the next spring, there was a sudden increase in pressure on my optic nerve and my vision suddenly dropped off. Within 2 weeks, I went from driving to needing to be led around. None of my neuro-ophthalmologists had heard of this happening before. Within weeks, I started radiation treatment. I also had two surgeries to relieve the pressure on the optic nerve. No one knew what the prognosis would be. We were in uncharted waters.
For 3 years, I slowly regained vision. Then my vision stabilized at a very low level, and I had to adjust to the new reality.
Price, pictured above at the Pont du Gard in France with his guide dog, Plymouth, enjoys traveling and has been to Europe twice since losing his vision.
D.P.: First, I undertook training to learn how to live independently with very little vision. I obtained my first guide dog, a black Labrador retriever named MacDougal, to help me get around and then began to re-establish my life and think about my future. My treatment, recovery, and training to live independently as a person with vision loss took several years.
When I returned to my studies, I converted my Ph.D. project into a master's thesis, as it was not feasible for me to go back into the field to collect more samples and perform laboratory work. I completed the analysis of the field data I had already collected with my father's assistance; he was my eyes and my hands. Since my father was not a geologist, we had to overcome many communication problems, but with his help, I completed the interpretation and defended my thesis, completing my M.S. in structural geology in 1998.
After that, I began to contemplate how I could continue in geology with my limited vision. Initially, I thought about areas where I could use computers to model aspects of Earth systems. I had learned to program computers as an undergrad and had enjoyed the work. However, at that time, and still today, the methods for rendering complex mathematics into a form usable by the blind are very clumsy.
Since I enjoyed programming, I began to think about the field of computer science. Access technology had developed to the point where I could work on computers. It is still not as good as it should be -- most application developers never consider taking the generally small steps necessary to make their programs accessible -- but the technology has reached a point that makes computer programming feasible.
I began taking some undergraduate-level classes so that I could apply to a graduate program. In one of those classes, we needed to use a programming language unlike any I'd ever used before. The language is Scheme, and it is based on nesting subexpressions within expressions. In class, the professor, Joe Zachary , stated that parentheses surrounded the expression but never mentioned that they also surrounded every subexpression -- he demonstrated this on the board. When I wrote my programs for my first assignment, I carefully placed parentheses around the expression, but I did not know to place them around the subexpressions. Needless to say, my programs wouldn't run.
I met with Joe to find out what was going wrong, and we began a discussion about learning how to program and how programming could better be taught. We agreed that it would be wonderful if, when learning to program, you could ignore the syntax of a programming language and focus only on the concepts. We decided that the best way to communicate the concepts was natural language. We brought Ellen Riloff , a professor who specialized in natural language processing, into the discussion, and my master's research project was born. My prototype converts English sentences into syntactically correct Java code. While no program yet exists to allow students to learn to program using natural language, this prototype and user studies indicate that it is possible. This research introduced me to several areas of computer science that I enjoy -- natural language processing, artificial intelligence, and human-computer interaction.
D.P.: I've always enjoyed learning, so returning to study a new field did not pose any problems for me. However, I have a very basic problem: I'm a visual learner. I have adapted and can learn many things by listening now, but I still have difficulty visualizing information best conveyed through diagrams when that information is conveyed through spoken descriptions. This made classes in the theory of computer science and computer hardware architecture very difficult for me. Fortunately, the faculty members in the University of Utah's School of Computing were very accommodating -- they always gave me as much time to finish assignments as I needed.
I'm in the process of finishing a master's degree. I completed my research in 2004 and defended in 2005. However, I'm currently finishing up the last part of my final course -- the course on the theory of computer science. It is one of those visual classes that has taken me a long time to finish. Working has greatly slowed down my progress as well: I'm currently working for the National Oceanic and Atmospheric Administration as part of a team trying to predict snowfall rates from satellite and weather forecast model data. This fall, I'll be starting work at a U.S. Navy research facility and look forward to working on new problems. ... I enjoy the process of examining problems, determining if they might be solvable, and working to find a solution.
D.P.: I still enjoy hiking and backpacking. I have also developed a love of tandem cycling. I still ski and have been helicopter skiing twice. [Skiing as a person with vision loss requires a guide.] I also enjoy traveling and have been to Europe twice since losing my vision. Bottom line: You have to make changes when you suffer from a disability, but you can't let it slow you down or keep you from doing the things you love.
Robin Mejia  is a science writer in Santa Cruz, California.