There are many reasons a cat might become blind, and some of those reasons aren't very pleasant to think about. As sad as it is for them to lose their sight from a possibly untreated disease process, or to be born blind, it's much more disturbing to learn of those who are victims of cruelty.
Blind cats who end up at shelters may be higher on the list to be euthanized, since they are often harder to find homes for.
I rescued a blind kitten from a cruelty situation several years ago, but no one wanted a "defective" cat. So she is a personal pet now.
Living with her has taught me much about how to handle her special needs. What amazes visitors is how well she has adjusted to her dark world. She even trusts humans again and is very sociable, and playful.
Without the ability to see, one must realize that the other senses become that much more important, such as smell and hearing... and touch.
Here are some tips for handling a pet with limited or no sight:
1. Approach with respect. Do not startle the pet by sneaking up and touching her. It helps to speak first, and perhaps touch her whiskers to let her know how close you are, before petting or picking her up.
2. When new in your home, let the pet get used to one room first, then increase her territory gradually, as she builds a mental map of the layout or floorplan. Also, try not to rearrange furniture too often, or too drastically different.
3. If you have other pets in the home, allow them to become friends, if possible. Sometimes a blind pet can be helped by having a "guide" buddy.
4. For exercise, use toys that make noise, or have a definite scent, like catnip.
For more information on this subject, drop by my website, The Problem Cat to learn more about Special Needs kitties.