Myopia and hyperopia are mainly due to the curvature of cornea and lens surface is too large (myopia) or too small (hyperopia), and the axial length is too long (myopia) or too short (hyperopia). When the diopter changes by 6.00 degrees for every 65438 0 mm change in corneal curvature (that is, myopia increases by 6.00 degrees for every 65438 0 mm decrease in corneal curvature; Hyperopia is the opposite); When the axial length changes 1mm, the diopter changes by 3.00 degrees (that is, when the axial length increases 1mm, myopia increases by 3.00 degrees; Hyperopia is the opposite). Astigmatism eye is mainly caused by the curvature inconsistency of each meridian on the surface of cornea and lens, and also by the abnormal refractive index of cornea or lens.
Many patients do not use astigmatic lenses (cylindrical lenses), although their vision is reduced, but they have no astigmatism symptoms (monocular ghost). If they suddenly add astigmatism lenses (cylindrical lenses), they will not adapt and their vision will be distorted. At this time, they can convert the cylindrical mirror into a spherical mirror (myopia or hyperopia correction lens) through a compromise scheme, but there is no discomfort, such as 0. Astigmatism 50 degrees, not suitable for wearing, put 0. The 50-degree cylindrical mirror is converted to 0 degrees. The goggles of 25 are more comfortable. This is determined according to everyone's biological condition and mental state. When the mental state is good, the comprehensive analysis ability of the visual center is relatively strong, and the tolerance of the cylindrical mirror is good. When the comprehensive analysis ability of the visual center declines, even the extremely low cylindrical lens (astigmatism lens) can't tolerate it. Therefore, patients with astigmatism do not have to use astigmatism lenses (cylindrical lenses). When all spherical lenses (myopia and hyperopia degrees) are used, even if there is astigmatism, the cylindrical lens is not used to correct it, but half of the astigmatism degree is added to the spherical lens.
According to your reaction, the results of your two optometries are actually the same. Half of the cylindrical lens plus the spherical lens is actually the degree of the cylindrical lens, which is 0. Myopia is 50 degrees, 1. The combined luminosity of cylindrical lens at 00 degrees is the same. Half of the time, astigmatism is caused by the different curvatures of each meridian of the cornea, so it is organic and unlikely to change (of course, some teenagers who are still developing may change the cornea), so your optometry results may not be accurate once. If there is no discomfort, don't worry too much. If you feel uncomfortable, I suggest you change your optometrist to re-optometry.
I hope I can help you. Please call me if you have any questions.