Betty Cook, a lab assistant at the Stanford Research Institute, is shown taking a "blink test" as part of a project to track down smog in Stanford, Calif. on April 27, 1949. The test gauges eye irritation through photoelectric cells that record each blink of the eyes. The plastic helmet is filled with measured amounts of smog. Cook wears glassless goggles that act as blink recorders. She reads a book to give uniform reaction conditions.The smog project is being conducted by the Air and Water Pollution Laboratory of the Western Oil and Gas Assn.
Ernest K. Bennett / Associated Press
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