I make you own dots with scrap materials I get from a membrane switch manufacturer (translucent membrane and clear cling material). Colorless for day light and black for shooting under the lights. I make the black dots "magic" by applying the cling material to a piece of 1 1/2" wide black electical tape. I cut the dots with a 3/4" gasket punch.
I keep a roll of clear scotch tape in my shooting box for my 4-H kids. It's translucent instead of transparent. It's cheap, leaves no residue, and works well when trying to train a dominant eye to take over for the youngsters. The other good thing about it is that I can adjust the "size" of the dot so it only covers what is needed.
I used the dots when they first came out approx. 20 years ago. They were very inexpensive. When the price went rediculous,I went to translucient scotch tape. Position it so you see the target come out with both eyes. Works fine for me. Clyde