Normal patterns of déjà experience in a healthy, blind male: challenging optical pathway delay theory.

We report the case of a 25-year-old healthy, blind male, MT, who experiences normal patterns of déjà vu. The optical pathway delay theory of déjà vu formation assumes that neuronal input from the optical pathways is necessary for the formation of the experience. Surprisingly, although the sensation of déjà vu is known to be experienced by blind individuals, we believe this to be the first reported application of this knowledge to the understanding of the phenomenon. Visual input is not present in MT, yet the experiences he describes are consistent with reports in the literature of déjà vu occurrence in sighted people. The fact that blind people can experience déjà vu challenges the optical pathway delay theory, and alternative causes are briefly discussed.