There are several contradictory explanations of the expression "Here's mud in your eye!". I am glad to say that the one that fits best the scientific development described here was mentioned at least twice, and here is its source:
After saying this, he spit on the ground, made some mud with the saliva, and put it on the man’s eyes. “Go,” he told him, “wash in the Pool of Siloam” (this word means “Sent”). So the man went and washed, and came home seeing.I am happy to state that there is no need to put mud on a blind person's eyes anymore, even if a most distinguished rabbi (like the one in the case quoted) does it. Here is why:
Israeli scientists have developed a technology that may enable people who are blind from birth to see, with the help of a bionic contact lens.Read the rest in the original article.
The new technology, developed by a team at Bar-Ilan University, has yet to receive approval for clinical trials, but its feasibility is currently being tested on seeing individuals, with the aid of a model simulating the bionic lens.
The technology consists of a tiny camera that receives visual information from the environment and transmits signals to a bionic contact lens. The lens passes the signals via electrodes to the cornea and from there to sensory brain areas, generating a stimulus that simulates visual information.