You need two sharpened pencils or two thin knitting needles or two identical fine-tipped…

You need two sharpened pencils or two thin knitting needles or two identical fine-tipped pens.
Hold a sharpened pencil in each fist horizontally (back of your hands facing the ceiling, with the tips facing each other). Keep your elbows bent so your hands are about 18″ in front of you and at about eye level, spread your hands about 12 inches apart with the tips of the pencils facing each other.
Close one eye
and bring the pencil tips together until they touch. Now, repeat the exercise with both eyes open.
Explain what happened and
WHY
it happened