This results in images of distant objects being spread out to a small spot known as the Airy disk.

They are like photographs: true images of real objects.

Unlike perceptions, which are particular images of individual objects, concepts cannot be visualized.

The image of far-away objects is therefore fuzzy, though close-up vision can be good.

Thus, they can deliver sharp images of objects that previously were hidden or only discernible at close range.

In its current form, it will be able to create images of objects on the harbor's floor, he said.

In our minds we often have images of objects, events and settings.

His head no longer throbbed; all images of objects about him were clear and well defined.

For example, if the head is moved, the image of nearby objects shifts more than those further away.

This has the effect of producing magnified images of close objects.