1.Previous
3.Next

of the object is formed on the retina between points and . (See visual system). For small angles, the size of this retinal image is

:

where is the distance from the nodal points to the retina, about 17 mm.

Examples

If one looks at a one-centimeter object at a distance of one meter and a two-centimeter object at a distance of two meters, both subtend the same visual angle of about 0.01 rad or 0.57°. Thus they have the same retinal image size .

That is just

1.Previous
3.Next