In photo # №2,3-tabs are sold in this form, without glass eyes in the center.
The store has glass cabochons and hemispheres of different sizes. And also, you can make glass eyes from those versions of the iris that are presented in the store or at your request (you need a photo in jpg format, good quality)
The size of the tabs:
15*8 mm (diameter and height): 8 mm recess.
19*9 mm (diameter and height): recess: 10 mm.
24*11 mm. recess: 12 mm.
27*12 mm. recess: 14 mm.
2. In the recess of the tab paste the image with the iris of the eye and fill it with resin. Or, if you draw well, draw an acrylic iris yourself and then, after drying, fill it with resin.You can add glitter, pigment, etc