Myopia (my-o'-pi-ah). (Gr. myo = close -f- ops =eye.)

An optical defect of the eye which causes parallel rays of light to focus in front of theretina, with the muscles of accommodation atrest. It is also known as Brachymetropia and Hypometropia. A correction (concave lens) isnecessary before normal vision can be obtained.In the early days the Greeks noticed that allnear-sighted persons could see better at a dis-tance by half closing the eyelids (squinting).hence the name myopia. The eyeball maybe too long (axial) or the refraction too great,causing the parallel rays to cross and meet theretina as divergent rays, which form a circle ofdiffusion, and so cause a blurred and indistinctimage of the object.

Source: Ophthalmic Dictionary including pronunciation, derivation and definition of the words used in Optometry and Ophthalmology by James J. Lewis, Oph. D. Professor of Optometry in the Northern Illinois College of Ophthalmology and Otology, Chicago.