An axial 180 degree tends to mean that the astigmatism is on a horizontal axis. Axial 180 degrees and axial 90 degrees can be converted to each other, but only if the patient is most comfortable with them, so it is important to have the patient try on the glasses before making the conversion and use whichever axial position is most comfortable. If you get the axis position wrong, you can easily experience glare, dizziness, and other uncomfortable manifestations. However, before fitting, it is best to have an astigmatic optometry to see the true refractive state, to see if there is myopia, hyperopia, or astigmatism. If the degree of astigmatism is relatively large, it is best to check the corneal topography to rule out the possibility of cone cornea. It is very crucial not to make a mistake in the axial position, once a mistake is made, the spectacle lenses may need to be refitted.