Covering your eyes for hours causes hallucinations

On A study 2004, scientists from the Harvard Medical School blindfolded a group of 13 people they would have to go blind for five days. Throughout these 96 hours, these people reported on their experiences with the help of a tape recorder. The selected subjects were men and women between the ages of 18 and 35 with no medical history of cognitive dysfunctions, psychosis, or ocular pathology.

None of these people took medication. The results indicate that total deprivation of light on the eyes is sufficient to produce visual hallucinations in a few hours.

Study data

During this experiment, 10 of these 13 blindfolded people (77%) experienced visual hallucinations. These strange images varied in intensity and complexity, some consisting of simple points of light and others of figures, such as an Elvis Presley of light. Furthermore, none of these hallucinations referred to past experiences, they were new images.

Some examples:

Subject 1 (female, 29 years old). She experiences a single hallucination, 12 hours after starting to wear the bandage. It occurs while in front of a mirror, and consists of a green face with large eyes. She is very frightened by this vision.

Subject 5 (female, 29 years old). During the first day she sees circles of light, an image that will be repeated throughout the week. On the second day she has the sensation of seeing her arms and hands moving and leaving a trail of light when she actually moves them.

Subject 6 (man, 34 years old). Reports on numerous hallucinations experienced while she listens to the Mozart Requiem: the outline of a skull turning until it is looking at the subject. On another occasion, also listening to the Requiem, she sees the silhouette of someone wearing a kind of ceremonial mask and a headdress. This person has their face turned upside down and their mouth is open. In a third audition of the same piece of music, she sees an older woman with a very wrinkled face and a threatening look. She is sitting on the seat of an airplane and is wearing a red eye shield similar to the one people wear who have to protect themselves from X-rays. Then this person's face takes the shape of a mouse's face. Throughout the days the hallucinations continue, some of them strobe effect.

Subject 8 (female, 20 years old). At 12 o'clock she suddenly begins to experience hallucinations. Some consist of figures that transform, such as a butterfly that metamorphoses into a sunset, into an otter, and finally into a flower. She also sees cities, lions, and sunsets so bright that she "can barely look in her direction." All these hallucinations have movement. She puts a lot of emphasis on the beauty of some of these appearances: "Sometimes they were much prettier than anything I have ever seen... I wish I could paint. "

Subject 9 (man, 27 years old). She sees flashes of light for the first 24 hours. She later informs her that she sees glowing peacock feathers and buildings of light.

All hallucinations ceased when the bandage was removed or a few hours later. These experiences can be explained as the result of a restructuring of the nervous connections of the brain, which tries to adapt to the lack of light. It is a process that can resemble the one that produces the syndrome of the Ghost member in people with amputated limbs.