Astigmatism is correc ted by the use of

Options

A. Convex lens
B. Concave lens
C. Cylindrical
D. Surgery

Answer

### Step-by-Step Solution:

1. **Understanding Astigmatism**:
- Astigmatism is a refractive error of the eye where light does not focus evenly on the retina. This results in blurred vision and can cause eye strain and headaches.

2. **Identifying Symptoms**:
- Common symptoms of astigmatism include blurred vision, eye strain, and headaches. These symptoms arise because the light entering the eye is not focused properly.

3. **Causes of Astigmatism**:
- The exact cause of astigmatism is not fully understood, but it can be related to hereditary factors. The condition is often due to a deviation in the spherical curvature of the eye.

4. **Types of Astigmatism**:
- Astigmatism is categorized into two main types:
- **Corneal Astigmatism**: This occurs when the cornea has an irregular shape.
- **Lenticular Astigmatism**: This occurs when the lens of the eye is distorted.

5. **Corrective Measures**:
- To correct astigmatism, specific types of lenses are used. The most effective correction is achieved with **cylindrical lenses**, also known as toric lenses. These lenses are designed to compensate for the uneven curvature of the cornea or lens.

6. **Conclusion**:
- Based on the above information, the correct answer to the question "Astigmatism is corrected by the use of" is **Option C: Cylindrical lenses**.