What type of astigmatism is characterized by more power in the horizontal meridian?

What type of astigmatism is characterized by more power in the horizontal meridian?

• A. Oblique astigmatism
• B. Irregular astigmatism
• C. With the Rule astigmatism
• D. Against the Rule astigmatism

Answer: (D)

The type of astigmatism characterized by more power in the horizontal meridian is known as "With the Rule" astigmatism. In this condition, the optical power of the eye is greater horizontally than vertically, which means that the horizontal meridian has a steeper curvature compared to the vertical meridian. This alignment typically occurs in the arrangement of the cornea, where the more curved surface offers a stronger refractive power in the horizontal direction. As a result, light entering the eye is focused differently along these meridians, leading to blurred or distorted vision. Understanding this concept is crucial because it helps in determining the correct type of optical correction needed for patients with different astigmatic profiles. The other types of astigmatism, such as Irregular and Oblique astigmatism, involve different characteristics of the corneal curvature and how they differ from "With the Rule" astigmatism, focusing on other orientations of power in the meridia.

The type of astigmatism characterized by more power in the horizontal meridian is known as "With the Rule" astigmatism. In this condition, the optical power of the eye is greater horizontally than vertically, which means that the horizontal meridian has a steeper curvature compared to the vertical meridian.

This alignment typically occurs in the arrangement of the cornea, where the more curved surface offers a stronger refractive power in the horizontal direction. As a result, light entering the eye is focused differently along these meridians, leading to blurred or distorted vision.

Understanding this concept is crucial because it helps in determining the correct type of optical correction needed for patients with different astigmatic profiles. The other types of astigmatism, such as Irregular and Oblique astigmatism, involve different characteristics of the corneal curvature and how they differ from "With the Rule" astigmatism, focusing on other orientations of power in the meridia.