Visual dreams. The way most people dream, the way some blind people even dream. Yet the few that have been blind since birth do not fit the same mold, dreaming in sound and other senses. Proven in a Danish experiment consisting of 11 adults blind from birth, 14 who became blind after age 1, and 25 control group adults who are not blind, the conclusion was drawn that the longer a person had been without sight, the less they saw in their dreams. This study also showed the differences between other factors of the blind and seeing’s dreams. In every sense the non-blind felt in their dreams, the blind felt more frequently. Eighteen percent of all the blind participants (both blind from birth and from later onset blindness) reported tasting in their dreams opposed to the 7 percent of the controls. An even larger difference, when it came to smelling in at least one dream 30 percent of the blind could smell compared to the 15 percent of controls. 70 percent of the blind reported the feeling of touch in a dream which was only felt by 45 percent of the non-blind. Finally, as there has been other research to suggest that the blind have heightened senses, especially hearing, 86 percent of the blind reported hearing versus the 64 percent of controls. And, more of the participants who were blind from birth experienced each of these senses in dreams.

Besides the sensory component of their dreams, the blind and the controls experienced the same thematic and emotional content in their dreams. The only other major difference was the amount of dreams reported as nightmares. The blind had nightmares much more frequently, 25 percent for those blind from birth, 7 percent of those with later-onset blindness, and only 6 percent of the controls. Researchers are unaware of why this happens as they only theorize why nightmares exist at all. However, they speculate that nightmares may happen to simulate threats as practice for those presented during the day. In agreement with the researchers’ theory, the blind often had nightmares of situations such as losing their guide dog or getting lost.

Sources:
http://phenomena.nationalgeographic.com/2014/02/26/how-the-blind-dream/
https://nfb.org/blindness-statistics
http://m.mentalfloss.com/article.php?id=22723