We all know that Thomas A. Edison, the world’s most
famous inventor, was deaf and had to struggle to communicate
during the latter years of his life.
Anyway he is credited with 1,093 patents. It was
learned that almost 400 of these patents were related
to the light bulb.
This means a deaf man invented a light bulb that
formed the basis of all of our flashing assistive
devices. Of course, helping the deaf, via these flashing
devices, was not what Edison had in mind, though!
It was just a lucky happenstance.