6 years ago227 views
How come it works? It is really down to physics. Let's take the example of a camera. The camera has a system that helps regulating the quantity of light that hits the sensor: it's called the diaphragm. The more the diaphragm is little, the more the depth of field will be big, this means that there will be less blurred pictures.
Actually, it's just like if the diaphragm acted like a filter, not allowing the peripheral ray of lights to get through, and just keeping the more direct rays. When a picture is blurred, the peripheral rays are the cause of it.
For your eye, it's the same: you have a clear central vision and a peripheral vision that is blurry. So, when you look through a little hole, like a diaphragm, the beam of light will be narrower, and you won't have such a blurry zone.
See without your glasses / vision test