astigmatism axis的意思|示意

Astigmatism and Axis： Understanding Refractive Errors

The terms astigmatism and axis are related to the refractive errors that can occur in the eye and cause blurred vision. To properly understand how astigmatism affects the vision, it is important to understand the different types of astigmatism and the role that the axis plays in it.

Astigmatism is a condition in which the eye has difficulty focusing on objects at different distances, resulting in blurred or distorted vision. The cause of astigmatism is due to the shape of the cornea. The cornea is the front surface of the eye, and it is usually curved in a symmetrical shape. If the cornea is uneven or misshapen, the light entering the eye is not focused correctly, resulting in astigmatism. People with astigmatism may experience nearsightedness (myopia) or farsightedness (hyperopia) at the same time.

The axis of astigmatism refers to the degree of curvature or distortion of the cornea. This is measured in degrees and is generally between 0 and 180. The axis for astigmatism can be determined by an eye doctor during a comprehensive eye examination.

In most cases, astigmatism is easily managed with the use of corrective lenses. People who wear glasses or contacts to correct astigmatism may need to choose between either a cylindrical lens or a toric lens. Cylindrical lenses are designed to correct nearsightedness or farsightedness, while toric lenses are designed to correct astigmatism. When ordering lenses for astigmatism, the doctor’s prescription will usually include an axis measurement. This indicates the direction in which the lens needs to be tilted in order to correct the astigmatism.

By understanding the terms astigmatism and axis, it is possible to better understand the conditions that affect vision and how they can be corrected. With the proper treatment, astigmatism can be managed, allowing people to have clear and comfortable vision.