I don't know how good his vision is, but Rocky definitely uses it.
 
When Rocky was a very young kit, for Easter a friend gave him so of
those Petco plastic balls with a pellet inside to make noise, some small
plastic Easter eggs and an Easter basket.  One ball was a dark red and
another was a light orange and I think there was another one in a
different color.  Rocky was obsessed with taking everything out of the
basket.  He would take each item out of the basket and every time he
did it in a particular order.  The red ball first, then the orange, then
the other ball, then the Easter eggs.  Every time he did it in the same
order, until he discovered that if he threw his entire little body into
the basket, it would turn over and everything would spill out at once!!!
He was about 10 weeks old.
 
Another way he uses vision is to judge distance when he's trying to jump
from my desk chair to the dresser.  Since the chair isn't always in the
same position, sometimes further away from the dresser, he definitely
looks carefully before he decides whether or not to make the jump.  He
never does this in the dark, so I assume their night vision isn't so
good, like a cat's.
 
But I always thought cats had better vision than ferrets, until I read
Bob C.'s post.
 
I have one of those pot holder gloves in the shape and colors of an
alligator and when you open and close your hand, it's mouth opens and
closes.  Rocky loves to play with this (probably because it bites!!!) and
I can wrestle with him and throw him around on the bed without either of
us getting hurt.  However if I really play rough, which he likes, he will
nip my arm above the glove (he's no dummy).  I have to look for a new one
because this he has torn this one in a couple of places, which are now
covered with duct tape so the stuffing doesn't come out in his mouth.
Most of the damage was done because he likes to bite in a certain place,
hold on and have me drag him around the bed.  It's so funny the way they
become limp when you drag them.  When he does that he always reminds me
of those mink body stoles they used to wear in the 1930s or 40s, where
the minks are hanging down.
 
I highly recommend those pot holders.  I just happened to have one before
I had Rocky.
 
Shron & Rocky
[Posted in FML issue 4216]