Are cows blind

No, not all. They can see quite well, quite often better than humans can, and can often notice things much sooner or that are not obvious to us than we humans can.

Very few, if any, are born blind, but a fair few can become blind from maladies later in life, such maladies as cancer eye or untreated serious cases of pink-eye. IBR (Infectious Bovine Rhinotracheitis) can also make cattle blind if not treated.