https://en.m.wikipedia.org/wiki/Voretigene_neparvovec
It’s a gene therapy delivered in a viral vector. They inject it (into your eye which much be fun). It appears to be one of the first approved gene therapies.
It just doesn’t seem to be commercially viable (colorblind-ness therapy was never persued because risk/reward/commercial aspects don’t work out IIRC).
Not necessarily. For example, consider that neurons in our auditory cortex aren't different from neurons in our visual cortex!
What is different about them (and the "subsequent" perceptual/conscious level) is that they receive different inputs, and have learned the systematicity of how these inputs behave in relation to the body's own actions.
This is related to the "Sensorimotor Contigency" theory of consciousness [1], which would predict that it should in fact be possible to process entirely different types of sensory input, given long enough exposure and a clear systematicity of the input signal.
[1] http://www.scholarpedia.org/article/Sensorimotor_theory_of_c...
https://www.wired.com/2007/04/esp/
and it seems the experiment has been updated:
https://www.theguardian.com/technology/2017/jan/06/first-hum...
“As we walk down the street there’s radiation, X-rays, infrared and ultraviolet, as well as the electromagnetic field of the planet. So we want to create new senses to become aware of our environment.”
and
Harbisson, who is colourblind, has an ‘eyeborg’ that allows him to “hear” the light spectrum (including infrared and ultraviolet), while Ribas has a sensor in her elbow that vibrates when an earthquake occurs anywhere in the world.