I've been taking care of some outdoor kittens for the past few months now and they've grown big and playful. For being kittens of a stray living outdoors, they look and act incredibly healthy, but their eyes seem to goop up a lot more than I'd like to see. It's generally yellowish in color and when dries can cause their little eyes to seal. When this happens I've used a warm wet gauze piece to gently clean and open up their eyes. But I'd like to find a remedy to clear this problem up for them. Any suggestions??