A sphere smaller than the pupil is seen as more than half
Such a small object hides no remote object, and shows more than half—more so the nearer it lies
This page continues the geometry of vision. An object smaller than the pupil, set before the eye, hides no remote object from that pupil. Moreover, no spherical body smaller than the pupil is ever seen by a single pupil as less than half, at whatever distance; it is seen as more than half the nearer it lies, and less so the farther away. Two diagrams of the eye with spheres and visual lines accompany the text, along with a third analogous figure.
On this page
A sub-pupil object occludes no remote object
An object smaller than the pupil, placed before the eye, hides from that pupil no remote object. Because it is narrower than the pupil, sight passes around it to whatever lies beyond.
A small sphere is always seen as more than half
No spherical body smaller than the pupil is ever seen by a single pupil as less than half, whatever the distance. It is seen as more than half the nearer it is, and less so the more remote it is from the eye.
Diagrams of the eye and small spheres
Two constructions show the eye with a sphere and its visual lines, one above and one below, demonstrating the portion of the sphere taken in by a single pupil. A third analogous figure is indicated.