Black holes are just the result of imploding stars of sufficient mass that end up so dense, that not even light can escape the gravity. Also, keep in mind that stars are just contained nuclear explosions, with sufficient enough gravity to keep said explosions contained. Once the fuel burns off (hydrogen turning into heavier elements that can no longer be used; mostly iron), the gravity exceeds the outward pressure of the nuclear furnace and the star collapses in on itself.
In some cases, the resulting implosion will end in a neutron star (pulsar, magnetar, etc.), but some will become black holes. Some of these will emit visible light and some won’t.
So, a black hole is basically not really a hole, as much as an exceedingly large mass that is crushed into an infinitely small space, which is supposed to tear a hole in space itself. In either event, black holes still emit “light”, but in the form of gamma radiation. We just perceive light in a very myopic spectrum...radio waves are light, X-Rays are light, etc..