Defects of vision (ametropia)
Ametropias are of two types:
Spherical vices (asosymmetric ametropias), which are myopia and hypermetropia . In these vices, the light rays coming from an object come into focus on a single point, which in front of myopia and in the hypermetropia is behind the retina.
Astigmatic vices or accommodation defects (astigmatic or accommodative ametropias), which are presbyopia and astigmatism . In these vices, the rays do not focus in a single point of the retina, but form two perpendicular lines which are therefore not situated on the same plane.
See also: The dark circles
| Eye | Myopia | farsightedness | Presbyopia | Astigmatism | Glaucoma |
