A cataract will allow enough light to enter the eye to have the iris constrict and have the pupil get smaller. The image is less clear than if there no cataract, but light perception and the associated pupillary size change remains.

<img src="/ubbthreads/images/graemlins/offtopic.gif" alt="" /> <img src="/ubbthreads/images/graemlins/offtopic.gif" alt="" />I want Blob.... love them fatties!!
B

Talked with a few vets in OZ -
Strongly suggest getting this glider checked by an opthalmic specialist. These may be congenital cataracts or lenticular opacities.
There is likely to be a genetic basis as it appears very common in the US glider's.
Can comment no further without actually seeing them, hence see a specialist to obtain a proper diagnosis.

Looking at these pictures, I noticed that his tail is completely cream colored. There is no black tip. There was another post a while ago about a glider about a simular glider with an all cream tail that appeared to have cataracts. I wonder if they originated from the same breeder. One of my silver tailed girls appeared to have cataracts when I first got her. The vet thought that is was something else (I forget now) and prescribed some kind of eye drops and the cloudiness cleared up.

I am off to search for the other post about the cream tailed glider with cataracts. Some people speculated that the glider got into bleach, bleached its tail and damaged its eyes. I believe the there is a link between the cream colored tails and the cataracts. Do the other related joeys have black tips on their tails or are they also completely cream colored?

Found it here

It is interesting that KiKi mentions in that post that she found an article linking white tails and cataracts.