The flash of a camera is bright enough to cause a reflection off the human retina -- the red we see in these photos comes from the blood vessels in the eye. Learn more about red eyes and cameras in this HowStuffWorks podcast.
Welcome to the Brain Training Podcast, the daily audio workout for your head.
In this podcast we have two games for you, each with three rounds which get progressively harder.
To enjoy the full experience, relax, and avoid distractions whilst you listen.
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