What is astigmatism line level?
Due to the irregular curvature of the cornea in patients with astigmatism, there may be abnormal refraction.
Line position refers to the position of refraction. Simply speaking, it describes the position of astigmatism. It does not represent the depth of the degree.
If you want to wear contact lenses comfortably and see clearly, you should not only pay attention to the power of the glasses, but also pay attention to the line position and power of the astigmatism Con , both of which are closely related to the comfort of wearing them. People with astigmatism may experience discomfort and blurred vision when wearing contact lenses. But what does the astigmatism Con line mean ? What is the maximum degree of astigmatism Con ? Next, I will introduce you to the information about Astigmatism Con . 
Before introducing astigmatism Con , let me first introduce the causes of astigmatism. Astigmatism is different from myopia and hyperopia. Myopia and hyperopia are refractive errors, which are caused by the eyeball being too long and too short respectively. As a result, the light of the image cannot be focused on the retina, and the light source cannot be converted into clear visual signals and transmitted to the brain. Astigmatism is This is because the horizontal and vertical curvatures of the cornea are inconsistent. When the curvature of the cornea is irregular, light cannot focus after entering the eyeball, resulting in blurred vision.
Generally speaking, there is a slight deviation in the vertical and horizontal curvature of the normal human cornea, but this does not cause the light to fail to focus and blur the vision. The causes of astigmatism are mainly divided into congenital and acquired. Congenital astigmatism is inherited from parents, while patients with acquired astigmatism are caused by bad living habits, such as reading or using smartphones in a dim environment, looking at books slanted, rubbing their eyes, and having eyelashes fall down. Insertion, etc. will affect the curvature of the eyeball, resulting in astigmatism.
What does astigmatism Con line mean ? What is the difference between astigmatism Con and ordinary Con?
Since the causes and effects of astigmatism are different from those of myopia and hyperopia, the lens design of astigmatism Con also needs to be adjusted accordingly to correct the patient's vision. Ordinary contact lenses will only be marked with "D", which is the diopter of the eyeball, and will also be marked with a plus or minus sign. A plus sign indicates farsightedness, and a negative sign indicates myopia.
Astigmatism Con will have two additional parameters, "CYL" and "AXIS", which respectively correspond to the astigmatism degree (Cyclinder) of Con and the astigmatism Con line position (Axis). Astigmatism, like diopter, is also marked with a plus or minus sign to differentiate between nearsightedness and farsightedness. There is no positive or negative distinction between eyeball line position, and astigmatism line position means the direction of astigmatism.
What is the maximum degree of astigmatism Con ?
Although the design of contact lenses breaks the frame of traditional glasses and allows people with poor vision to get rid of the constraints of traditional glasses, contact lenses are not suitable for everyone. Under the current technical limitations, both ordinary Con and astigmatic Con have maximum height limits. At present, the maximum diopter of Con is 1200 degrees, while the maximum diopter of astigmatism Con is 225 degrees, and the maximum line level is 180 degrees. In other words, even if the astigmatism is 300 degrees, a person with astigmatism can only wear contact lenses with a maximum of 225 degrees of astigmatism. In addition, the power of contact lenses is not as accurate as traditional glasses. The diopter is one level every 25 degrees, the astigmatism is one level every 50 degrees, and the linear position is every 10 degrees. 
The above introduces the difference between ordinary Con and astigmatism Con , the meaning of the line position and the maximum degree of astigmatism Con . Remember not to wear contact lenses with different powers, otherwise it may cause permanent damage to the eyes.