It is well known how an image is produced in general: You need at least two rays (in geometric optics) to form it, see the image next:
But I wonder about these images:
As you can see, in the upper picture, the generated image on the retina is achieved by, let's say, two rays that meet in a focus around the center of the eye. But in the lower picture, the image is generated while the focus is on the retina, so there are, in terms of geometric optics, no two rays to construct an image. It seems, that the lower version results in clearer images. From my understanding, there shouldn't be an image.
Using more sources provide a more insight view in regard to medical aspects:
So the mechanism in picture 1 seems to be an error of the eye. However, according to common geometric optics, there are two rays needed that do not meet in the focus:
So where am I'm wrong? I know it's quite basics but I can't get my head around it. Maybe it's more a question of medical matters as rays, focused on the retina, will deliver images behind it? Or is it physics I lack?