Our Rocky was diagnosed with juvenile cataracts at the age of six months.
Upon hearing this we immediately asked the vet (not knowing any better)
how we would know when his quality of life would get to the point that
we should let him go because of the sight loss.  The vet then sat us down
and explained to us that ferrets are one of the most adaptable animals
when it comes to losing their sight.  He explained that they mainly go on
smell and sound anyway, and that the main thing was not to "rearrange his
world" unless we had to.
 
We lost Rocky January 7, 2002.  Needless to say he was blind as a bat.
But unless you looked at his eyes which were white with cataracts you'd
never have know it.  A lot of people that met him never knew that he had
been blind most of his life.  Up until the last three or four months of
his life he danced and dooked with the best of them!!  He ran and played
with the others just like a sighted ferret would, and even seemed a little
less clumsy than our other kids!!!  The only thing I did different was to
make sure I talked to him and called him by name and let him smell my hand
before I touched him so as not to startle him ... especially if he had
his attention elsewhere, like figuring how to steal ALL of the raisins!!
It never seemed to affect how he played with the rest of the gang in the
least, and I don't think any of them even noticed a difference.
[Posted in FML issue 3777]