Question

a cat is blinded in one eye in a fight. when this cat later sexually reproduces with another cat, how will the blindness affect the offspring?

Answer 1

There will be no effect on the offspring because the blindness was the result of an injury and not related to genetics. If the parent cat was blind at birth, then depending on the cause, the blindness could *possibly* have been genetic, but that is not the case in this situation.

Answer 2

The offspring will not be affected by the blindness.

We have to, of course, assume that there is a very slim possibility of the offspring being born blind.

However, the cat was blinded in one eye in a fight, but not from birth. 
Outside influence, not genes, caused the cat to be blinded. 

So, since genes didn't affect the cat to be blinded in one eye, the offspring will not be affected in terms of blindness by any passed on genes.