Line of Sight

An expansive and illuminating perspective on vision, and how it has shaped humankind.

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Color does not really exist in the world around us: objects reflect the sun's rays in different proportions; our eyes collect those reflected rays and our brains apply color. But why invent color?

In Line of Sight, scientist Andrew Parker explains his famous "Light Switch Theory," which holds that the evolution of vision caused the "Cambrian explosion" more than 520 million years ago. He examines the origins of the eye in our earliest animal ancestors and how modern sight developed over the course of millions of years. He then delves into how vision has driven the evolution of specifically human characteristics, from consciousness to artistic expression, language development, and emotion. Finally, Parker considers how we might use evolutionary knowledge of the eye to improve our lives and society, from introducing morale-boosting colors and shapes in hospitals to improving technologies such as the motion-detecting systems crucial for self-driving cars.