In the ninth century AD, the Arab scientist Ibn al-Haytham finally worked out the correct laws of optics and declared that extramission was wrong. Light enters the eye in straight lines to form an image. Despite that definitive scientific answer, a folk belief in eye beams persisted. A thousand years after al-Haytham, a belief in an “evil eye” is still common across many cultures, along with a lucrative trade in amulets that can protect you from it.13 In our culture, Superman has X-ray vision, which somehow shoots out of his eyeballs and burns things. Almost everyone has had the spooky feeling
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