Ophthalmic terminology
Diopter : the unit used to measure the focusing power of a lens.
Emmetropia : good vision without the need for glasses.
Hypermetropia : long - sightedness ( impaired close - up vision )
Intraocular : inside the eye.
Myopia : shot - sightedness ( impaired close - up vision ).
Pseudophakia : the eye's natural lens has been removedand an artificial lens has been implanted.
Refraction : the ' bending' of light rays to bring them into focus.