Have you started using any new products in your house or a new food? If it's worse lately it might be something that you have introduced to your home lately.
You can get hypo-allergenic foods. Making sure your vacuum filters are cleaned often (same as for asthma). Oatmeal bath might help.

My cat is allergic - she gets all watery eyed in spring. I think it's kind of wierd that a cat has allergies - I thought they were meant to cause them not suffer from them.