Injury sub for lost contact lens?

[BayStateRef]

Girls varsity. A1 is fouled while shooting. Before administering the free throws, she tells the officials that she lost a contact lens. After hunting, it is not found. She stays in the game. First free throw hits the backboard with a thud, not even close to the rim. Second hits the rim...but not close.

Team B gets the rebound, starts a fast break and scores. On next possession, A1 is again fouled in the act of shooting. Before she shoots the free throws, head coach of A asks to replace A1 because she has lost a contact lens and cannot see. We allowed the substitution and before administering, tell B coach of the decision. He had no problem. (Sub missed both free throws).

The allowance for a sub to replace an injured player before a free throw (8-2) makes no mention of not being able to see the basket. Did we handle it properly?