Today, in these vision centers, technicians take eye scans and send them to doctors in Madurai for review. Automated diagnosis can streamline and expand the process, reaching more people in more places -- the kind of "McDonaldization" espoused by Dr. V. The technology still faces regulatory hurdles in India, in part because of the difficulty of navigating the country's bureaucracy. And though Google's eye system is now certified for use in Europe, it is still awaiting approval in the United States. Luke Oakden-Rayner, the director of medical imaging research at the Royal Adelaide Hospital in Australia, said these systems might even need new regulatory frameworks because existing rules weren't always sufficient. "I am not convinced that people care enough about the safety of these systems," he said.

Doctors can sometimes make a diagnosis when faced with cataracts and blurry eye scans. The Google system still struggles to do this. It is trained largely on clear, unobstructed images of the retina, though Google is exploring the use of lower-quality images. Even with this limitation, Dr. Kim said, the system can augment what doctors can do on their own. Aravind already operates small vision centers in many of the cities and villages surrounding Madurai.