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Human eyes are very strong. While in space, astronauts have seen the wakes of ships at sea. And even people who don’t have good eyes can sort through complex images.
But human eyes are weak compared to the eyes of some other animals. Snakes, for example, see infrared light. That’s invisible to humans. But people have made up for their visual limits by inventing machines to help the eyes. Some magnify things we cannot see. Others look at faraway places we can only dream of seeing on our own.
