Blindness can be a condition with which someone was born, or can be something acquired late during one's biological existence. The very condition of blindness varies: some blind people get to, at least roughly, see shapes and forms (considered as "legally blind", for example, in cases of extremely high myopia unable to be corrected with lenses, or some cases of macular damage)
In the one hand, racism isn't restricted to physical appearance. There is racism against accents or the manner someone talks. There's racism against the kinds of food eaten by certain cultures (perceived through smell and taste).
On the other hand, blind people themselves are often victims of prejudice.
Having said all this, I'd say racism doesn't feel entirely correlated with sight. But maybe some correlation holds, and blind people would be more respectful and empathetic to others, especially given the prejudice they themselves experience.