He wasn't used to something so primitive as simple lenses.

A simple lens would not be able to reach very far, for instance.

In a simple spherical lens, each surface is a portion of a sphere.

Light that goes through a simple lens such as found in an eye undergoes refraction, splitting colors.

A simple lens consists of a single optical element.

Such lenses can produce images with much less aberration than standard simple lenses.

The mines were thermonuclear weapons, each fitted with a simple magnetic lens.

This combination produces a better image than a simple lens.

However, as the microscope objective is only used to collect light and not to form an image, it may be replaced by a simple lens.

In each section, the overall thickness is decreased compared to an equivalent simple lens.