Our nighttime fantasies are one of the many quirks of the brain that continue to confuse scientists, but there is one question that frequently turns up in both online question boards and scientific studies: How do blind people experience dreams?
A paper published in Sleep Medicine back in 2014 looked into the “sensory construction of dreams” among blind people to try and pry into this question. Neuroscientists from the University of Copenhagen gathered 25 blind people, 11 who were blind from birth and 14 who became blind after age 1, along with 25 sighted participants. Over the course of four weeks, they interviewed the participants about their dreams and asked them to fill out a structured dream diary when they woke up each day.
The dream diary asked all kinds of questions that you’re probably curious about yourself: What form do they take? What do they see in their dreams? Do they experience nightmares?
The study found that the blind participants reported a far richer and wider variety of senses in their dreams compared to the non-blind participants. By a considerable margin, they experienced far more vivid sensations of sound, touch, taste, and smell. The sighted people tended to just remember the visual sensation of the dream.
Those who had acquired blindness later in life – and therefore had experienced some vision – did report some visual dreams. The study noted many of these people “described an object or a scene verbally in such rich visual terms that the interlocutor began to doubt if these individuals really lacked vision.” However, the longer they had been blind, the shorter their memory and the more hazy their visual impressions were.
The emotions and themes of the dreams were more or less similar. There were no notable differences between the groups in how much they dreamed of positive and negative social situations or aggressive interactions.