Focus on an object across the room and hold up your thumb at arm's length. You will see a double image of your thumb. In fact, everything between you and the object, as well as everything beyond the object, is seen in double due to our binocular vision. Close one eye and the effect disappears. The brain knows to ignore these double images and concentrate on the viewed object.
Nothing is as good as perfect, unaided vision.
Pinholes can also require a certain amount of adaptation, and understanding the above characteristics of pinholes will facilitate making them a part of your life.