Dermo-optical perception

[7] In the early 20th century Joaquín María Argamasilla known as the "Spaniard with X-ray Eyes" claimed to be able to read handwriting or numbers on dice through closed metal boxes.

[7] Science writer Martin Gardner has written that the ignorance of blindfold deception methods has been widespread in investigations into objects at remote locations from persons who claim to possess eyeless vision.

Gardner documented various conjuring techniques psychics such as Rosa Kuleshova, Linda Anderson and Nina Kulagina have used to peek from their blindfolds to deceive investigators into believing they used eyeless vision.

[9] Life magazine reported on several cases on June 12, 1964, and on April 19, 1937, calling them "X-ray wonders", but all of them were found to be cheating when tested under controlled conditions.

This focused on Rosa Kuleshova of Nizhni Tagil, whose alleged abilities were demonstrated on a TV programme called Relay watched by over 40 million viewers.

Complaining that he was too excited to sleep at night, he opined that this was a "major scientific breakthrough" which would lead to an "explosive outburst of research" whose results were "bound to be revolutionary".

[12] Joe Nickell who has studied DOP has written "To date, no one has demonstrated convincingly, under suitably controlled conditions, the existence of X-ray sight or any other form of clairvoyance or ESP.

[3][13] Alleged positive results haven't been accepted by the mainstream scientific community due to procedures not being tight enough to prevent cheating by participants, problems with replicating the effect reliably, and concerns about the colors being recognized by the texture of the ink on the paper (people who are blind from an early age can recognize Braille patters that only have .2 millimeters of elevation above the paper, and the limit of relief distinction in fingers is still unknown).