Least distance of distinct vision

Least distance of distinct vision is the smallest distance between two objects that we can still see them as two distinct objects. For example, if we look at two small dots very close together, like two small ants on a sidewalk, we can still see them as two ants, even though they are very close together. The least distance of distinct vision is how far apart two objects have to be before we can no longer see them as two distinct objects.