A German Yid once traveled to the tzaddik Reb Pinchas of Koritz to request a bracha for his daughter who had suddenly become blind. "The reason," said Reb Pinchas, "is that her father is also blind and this is a hereditary disease." The Yid protested, "But my eyes are perfectly healthy, and I don't even wear glasses!"
The tzaddik explained that a sinner is the one who is truly blind. He warned the Yid that his entire family was in danger of losing their vision, for "One who gazes upon the face of a rasha, his eyes grow dim."
Hearing this, the Yid wept and resolved to begin conducting his life according to Torah, and upon his return to Germany, he made his home kosher in all respects. When the daughter was cured, she traveled to Koritz to see the tzaddik and donated money for the writing of two sifrey Torah.
ספורי חסידים זוין תורה עי 97
My own son was having issues with his feet and legs. It seemed kind of normal and we had normal medical procedures at first. But after many months and repeated doctor appointments, one of the doctors said that "this is so weird! I can't understand what is happening." From that moment on I became extra cautious in guarding my eyes all day every day (even while I am driving a taxi in New York City). Within 1 week, all of the casts and crutches and boots that he had been in for 6 months completely stopped, and thank God, so far, for the past month and a half he's able to walk around again without any artificial assistance.
I hope H' will keep helping further...