Eye Problem

I just noticed now that one of cat's eyes are somewhat watery and the lining and eye itself are a little bit reddish. I never thought about it now but the past couple of days maybe, she sometimes closes only the affected eye from time to time. Otherwise she seem healthy I didn't observe any discharge or anything.

Is it just some sort of injury from overzealous catplay? I have a 3 month old kitty who's very feisty and seem to want to play at every waking moment.

This is the best photo I can take, the left eye is the one affected.

It could be conjunctivitis, aka pinkeye, or it could be from rough housing.  Either way, an eye issue isn't anything you want to ignore, as it can lead to worse issues.  I hate to say it, but it's time for a Vet visit, especially since it's been several days and it isn't getting better.