There are a number of ways to add eyes to the face of your miniature needle felted dog. I used 2mm glass eyes on wire stems for my dog. You could sew or glue on appropriate sized beads (black works well) or felt black or brown eyes in place on the dog's face using bits of embroidery thread or roving fiber. If you use a shiny fiber like silk, the eyes will have a soft glow.
To Add Glass Eyes - to insert wire mounted glass eyes, cut the wire in half if the eyes are mounted on either end of the same wire. Insert the eye through the dog's head in the correct spot, aiming the wire so that it comes out near the base of the dog's neck. Pull the wire very tightly with a pair of tweezers, pulling the eye deeply into the dog's head, and clip it to a length slightly longer than where it emerges from the dog's head (about 1/8 to 1/4 of an inch longer, depending on the size of your dog's head). Bend the wire to a tight bend and feed the end back into the dog's head, just beside where it came out near the neck. The loop of wire should hold the eye in place in the dog's body. As you push the loop into the dog's head, the eyes should move back to the correct depth in the head. If not, adjust the loop or the length of the wire until your eyes fit correctly into the dog's head.
Safety Note: If the dog will be handled by young children, use felted eyes rather than wire stemmed eyes which could come loose and injure a child.
