From the “Something You Normally Don’t Think About” department —
It’s an interesting question I’ve never thought about. This is how the Smithsonian experts answered it —
In May 2014, three Danish researchers published a study in the journal Sleep Medicine under the title “The Sensory Construction of Dreams and Nightmare Frequency in Congenitally Blind and Late Blind Individuals.” They believe theirs was the first quantitative analysis of dreams reported by a relatively large number (50) of congenitally blind people, people who lost their sight after birth and sighted people.
Over the four weeks covered in their research, their congenitally blind subjects reported having dreams with content related to touch, hearing, taste and smell, but not sight—unless they had some residual perception of light and color, in which case their dreams included indistinct visual features. The subjects who became blind after age two and a half reported some dream content related to sight, but the longer a subject had been blind, the less the visual content.
The congenitally blind subjects reported that 25 percent of their dreams were nightmares, compared with only 7 percent for those who became blind after birth and 6 percent for a control group of sighted people. Even the congenitally blind subjects were surprised, because they didn’t think their nightmares were much of a problem in their waking lives. Their nightmares usually concerned everyday threats, such as crossing a busy street; the researchers said that the nightmares might help the subjects remember information vital to their survival. But everyone’s dreams were equally bizarre.
So if you ever wondered…
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