The person who made this technique was tyring to sleep or wild but there was a spider on the wall and he would close his eyse and ever 5 secounsd open them again to check on the spider(make sure it was keeping distance)

anyway all of a sudden this made him more sleepy or soemthing(ive tried it before to i went to sleep in like 5 minutes and became really sleepy).[/b]
I never understood how this technique worked until now.

The reason it worked so well for him was because he was focusing his attention at something in the physical world - he was constantly worried about that spider. All while his body his body fell asleep, he stayed awake because of his fear of that spider getting to close to him kept him conscious.