sensory substitution

neuroscientist bach y rita came up with the idea of sensory substitution to bring sight to the blind with a mesh of electrodes on the tongue or skin of the back.

fish mask

fish sense their environment through electric field receptors on the medial line running down their sides. capacitive sensors are easy to build, and such a sense would be useful in many situations, such as walking in complete darkness, not getting run over by cars while operating a wearable computer, navigating dense underbrush, detecting incoming missiles.

how best to interface these electric field sensors to the human sensory apparatus? tactile stimulation of the face and scalp immediately jumps out as a 360 degree spherical surface to represent the electric field of the environment.

  • weighted vibrating motors are established technology, but are bulky and limited in frequency response.

  • piezo buzzers promise instantaneous response (no inertia) a variable frequency output, and compact lightweight construction.

  • direct electrostimulation is even more compact and inexpensive, but carries complications from electrode biocompatibility, electrochemical leeching, and maintaining consistent contact.

near-infrared vision

Porphyropsin, a.k.a. 3,4-dehydroretinol, a.k.a. Vitamin A2

  • increases human eye sensitivity to light in 850nm-950nm range to perceptible levels

  • must be on vitamin A1-free diet

    • causes loss of sensitivity to blue light

night vision eyedrops

  • gabriel licina and jeffrey tibbetts showed improved night vision after applying 3.2mg of chlorin e6 and 6 units of insulin in 150ul of saline solution with 6% DMSO to the eye.

  • chlorin e6, a tetrapyrolle and a chlorophyll analog, has been used as a photosensitizer in laser assisted cancer remediation. The light amplification properties of the Ce6 are used to use the energy from a low power light source to destroy cancerous cells with literal laser precision. The reaction creates oxygen species which induce apoptosis in tumor cells. This lead to the concerns about the mixture, as it would be possible that bright or even ambient daylight’s amplified effect in the eye may harm the cells, potentially causing permanent damage.