Cat with eye problems

Question
I saw one of your answers about a cat with eye problems, and I hoped that with a more specific description, you might be able to narrow down a possible problem from the many you listed.
One of my cats has recently developed what looks like a milky, hazy film over one eye. The pupil appears smaller in this eye, and the iris, which is usually a golden colour, seems reddish. I know you're not a vet, but any advice that can help inform me before I got to my vet would be much appreciated. Thank you!

Answer
Sounds to me, from my experience, like it's uveitis.  This is an inflammation of the uvea, the globe of the eye.  The iris can change colors because of the presence of red blood cells, white blood cells, bacteria or scar tissue in the eye.  

A milky haze behind the cornea (the clear membrane over the iris) can be caused by fluid deposits in the eye, white blood cell deposits, fibrin (the beginning of scar tissue), or even lymphoma (widespread cancer).  It can also indicate glaucoma.

A milk hazy appearance ON the cornea could be the result of ulcers on the eye, the thinning of the cornea, or other problems like cataracts.

This is a serious symptom, so she should be seen to try to find the root cause.  Though many cases go with the root cause undiagnosed, some eye medication should be probably prescribed, as uveitis causes abnormal pressure on the lens and retina and can cause partial to full blindness quite quickly.