These three things are to be half-filled with lenses or rice.
The Flat Ends model has been designed to be stitched inside a baby toy.
Then I made another one with a handle, just for fun.
The solid one is here if you want to print it in spiral-vase mode.
In any case, don't fill them with something dangerous for a baby or a young child. You have been warned
Technical
I made mines with 0.8mm shell and 0.8 top and bottom, 40% infill.
I recommend to have a raft support because the base area is very small
You can pour the lenses or the rice during the printing or simply by pausing at a certain height.