A squirrel will open his eyes when he is between four to five weeks old, at first he can't see that good so he wont change that much, you will notice a difference when 5 or 4 days have passed.
hope...
My six baby hamsters (pups) are 16 days old today and this is the first day they started to open their eyes. One has eyes wide open, some just barely open, and one not open yet so it varies by...