Is it normal that i can will my vision to blur whenever i want?

Yes, due to focusing: If a person is under age 50, the normal focusing ability of the eye is intact, and he can focus at will even when not reading or looking at something at close range. If this is done when looking at the distance, the vision will appear to be blurred. It is usually doubled also, since focusing ability is tied in with the in-turning of the eyes to properly align themselves at near.