Although the Moon is Earth's only natural satellite, there are a number of near-Earth objects (NEOs) with orbits that are in resonance with Earth. These have been called, inaccurately but provocatively, second, third or other moons of Earth. NEOs include quasi-satellites that orbit the Sun in resonance with Earth, which appear to orbit a point other than Earth itself, such as the orbital path of the NEO asteroid 3753 Cruithne.
Definition of CONVERGENCE. 1. : the act of converging and especially moving toward union or uniformity; especially: coordinated movement of the two eyes so that the image of a single point is formed on corresponding retinal areas.
From Wikipedia, the free encyclopedia. Convergence insufficiency or convergence disorder is a sensory and neuromuscular anomaly of the binocular vision system, characterized by a reduced ability of the eyes to turn towards each other, or sustain convergence.rom Wikipedia, the free encyclopedia. Convergence insufficiency or convergence disorder is a sensory and neuromuscular anomaly of the binocular vision system, characterized by a reduced ability of the eyes to turn towards each other, or sustain convergence.