Patent astigmatism film

No In the refractive tissue of human eyes, only the lens and cornea can cause astigmatism, so astigmatism is only related to the cornea and lens, not to the retina. The morphology of cornea and lens is generally congenital, and acquired abnormalities are more common in trauma, so it is incredible that astigmatism increases due to glasses. It is more likely that the astigmatism of the previous match is low, not the previous eyes. Of course, the current 150 degree astigmatism is simply wrong and possible. Judging from your unprofessional optometrist, the possibility of false detection is probably not low.

There are always people whose eyeballs are not so perfect. The cornea or lens is high in some places and low in others. When light passes through these uneven lenses, it is not one focus but many, which is astigmatism. Matching astigmatism glasses is to find out where the high place is, and then add a concave lens at this position to offset astigmatism.

This kind of injustice is congenital and cannot be cured by artificial means, such as surgery. Although the high place can be cut off, no matter how perfect it is, it can't be smoother than the natural one. Therefore, there will often be some astigmatism after surgery, precisely because it will cause new unevenness.

Astigmatism has less obvious effect on vision than myopia. In other words, if there is no myopia, 100 degree astigmatism may still be able to see 1.0, but what he saw 1.0 has some virtual image interference. Moreover, astigmatism is mostly natural and it is not easy to increase the degree, so astigmatism is far less terrible than myopia and hyperopia.

Contact lenses can also be equipped with astigmatism, and the correction effect after wearing them is no different from that of the frame.