the same as you did the previous XXXX or U can add seed beads. Have fun

If you're talking about the round pupil of the eye, most people will stitch it with an embroidery stitch called a french knot. There should be a tutorial somewhere on you-tube that will show you how to make that stitch. Other times, I've simply made a regular cross stitch using black thread and then outlined the black stitch with one strand of black thread. It just depends on what you want to do. I will say that the french knot can be a little tricky for some people to do correctly but practice will make perfect!

Thanks for the answers. I think I'll just make an X.

I don't like doing french knots, so I use beads.

I'm with summerdawn - I use beads a lot as it gives "life and dimension" to my projects - especially when it is eyes or flower centers. Hope this helps you some. Welcome to cross stitch and if you have anymore questions be sure to bring them here - these stitchers are the best.
cheryl

Wonder if they make a flat-backed bead, like a tiny cabochon, for eyes...think it might be more pleasing to the eye than the round ones? :)

That's right - X marks the spot! LOL Only kidding, all good suggestions. French knots require a little practice but once you have down you won't want to stop doing them. I had to do hundreds once for a project and got addicted. If you only have to do one then it's not quite as important that it turns our perfectly - nothing to compare it to. Until I became more practiced I used beads. If it's a sort of home spun project then you could also use a tiny button. ECS has a nice selection of embellishments. I have also ordered from a company that sells all sorts of cross stitch embellishments. I can't remember the name. I'll look through my stash and see if I can find it. Hopefully, our fellow stitchers will know what I'm talking about and come to the rescue.