I have made an eye and i have created a bone to control its dilation. The bone has been made a driver to the shapekey called “Key 1”. When i apply a custom bone shape to the bone, the object does not ender nicely in the 3d viewport. Check out the image and see for yourself. Is there a problem with the graphic card? Or is it a bug? When i make a simple circle the custom bone shape, it becomes completely invisible.
The normals of the custom bone shape are not all pointing outwards. Select the shape, go into edit mode, select all (A) and recalculate (Ctrl+N).
Or set the display to wireframe in the bone properties