I'm going to show you how to take a scrap of cardstock and make a template for the eyes.
First, draw out the shape for one eye, cut it out, then place it on the doll and get an idea where you want the second eye to be. Mark a small X on the paper where the center of the eye should be.
Fold the paper in half to mark the center. The small X should be in the center of the eye that you've already cut out. Draw the other eye by drawing through the hole you already cut for the first eye. Then cut out the second eye.
I drew my eye shape freehand without a pattern. If your doll's eyes are a different shape, use the shape you need. Just make the template as I did, only with your eye shape.