If you've got the material, yup! I wouldn't really recommend Iron-ons though, as embroidery is a much nicer option.
If you do go with Iron-ons, its called "Printable Cotton" (not transfer sheets). You run the sheet through an inkjet printer, and print off the item that is going to be attached. Let it sit for about 45 minutes, then cut it out so that no white is showing where it shouldn't be! (eg, "outside" the eye). Lay it on the material (should be flat, don't attach it to surfaces that are curved or it'll bubble), and iron it on, following the settings the brand recommends.