Using the ray model of light helps us to model what happens when a ray of light enters in to the lens. right? but doesn't tell us how?
As you can see in this image the rays of light are converging to form a smaller or a bigger image. but what does really happen. To make my question clear let me give you an example. if give a computer scientist a 4 by 4 pixel image and ask him to enlarge by a factor of two, what he would do is make an 8 by 8 pixel image and fill every 2 pixel the color of the one pixel in the older image. By the same logic what do lenses do, do they increase the number of photons that are reflected from the object,(which sounds wrong, but to just give you what kind of answer i am looking for).