astigmatism is different, it is a non-spherically symmetric refractive index system. Different corneal astigmatism in the meridian aircraft with different refractive power. As the astigmatism of the corneal curvature is asymmetrical, so sent along the point source of light, refracted through the eyes tin no manner in the retina as a remove point. Meridian of the cornea to reach a different light, the eye tin no be simultaneously in focus, so called astigmatism. The outcome is caused by things favor perversion or blurred vision.

myopia and hyperopia: someone to form a clear picture (focus), the eyes must be reflected from the object to the incidence of inflection of light, so that the light falls instantly above the retina. Myopia can only watch near objects, far objects arise blurred for the picture is focused in front of the retina. Correct approximate is to dress a concave lens myopia, it will give the focus shifted back slightly after the light,chukka timberland Cheap Flights, Cheap Tickets, Ch,timberland sale, fair fall on the retina. Hyperopia because the anteroposterior diameter of the eye shorter. Close to the thing emitted light rays are focused back the retina, so it looks very fuzzy, can look only distant objects apparently. Hyperopic patients can wear lens, so namely the light inside the folded slightly bent to aid the light falls on the retina.

eye for the main symptoms comprise irregular astigmatism due to the refractive power of the same meridian plane is not the same, with the cylindrical lens improvement ineffective, to try contact lenses (contact lenses) improvement.

astigmatism correction usage,jimmy choo shoes online,3G 版ipad2 恢复4.3.5固件报1604过错, due to the type of astigmatism alter. For simple hyperopic astigmatism, and a certain degree ought wear the fitting axial convex cylindrical lens; for uncomplicated myopic astigmatism, and a certain degree should wear the appropriate axial concave cylindrical lens; for complex astigmatism, and axial degrees should wear appropriate convex convex (or concave concave) composite cylindrical lens; for mixed astigmatism, you should wear appropriate and suitable degree of axial punch made of composite cylindrical lens. But not matter what type of astigmatism is one eye, the glasses should be strictly fathomed axial cylindrical lens to correct the astigmatism in the meridian plane absences to be effectively corrected.

astigmatism: myopia and hyperopia are spherical refractive peccadilloes, it is spherically symmetric refractive system. This spherical symmetry of abnormal refraction, corneal interface, it is different in the meridian plane with the same refractive power.

sub-rule astigmatism and irregular astigmatism astigmatism 2,shoes for cheap, usually referred to as astigmatism generally refers to the rule astigmatism. Medical Education | network collected rule astigmatism constantly divided into the emulating 5 types: (1) unattached hyperopic astigmatism: a main meridian as hyperopia, the additional to face the chief meridian; (2) single myopic astigmatism: one meridian namely myopic cardinal,背心, To address the additional main meridian; (3) compound hyperopia astigmatism: two main meridians are hyperopic, yet alter refraction; (4) compound myopic astigmatism: two main meridians are myopic, but alter refraction; (5) merged astigmatism: a main meridian because hyperopia, the other main meridian namely myopic.