What is astigmatism?

Astigmatism is a common and correctable focusing error that causes blurred or distorted vision.

What Is Astigmatism?

In astigmatism:

• The cornea (or lens) has an irregular shape
• Instead of round like a basketball, it's shaped like a football
• Light focuses at multiple points
• Results in blurry vision at all distances

Types of Astigmatism

Corneal vs. Lenticular

• Corneal: Irregular cornea shape (most common)
• Lenticular: Irregular lens shape

Regular vs. Irregular

• Regular: Consistent pattern, correctable with glasses/LASIK
• Irregular: Unpredictable pattern, harder to correct

Axis Classification

• With-the-rule: Steeper curve is vertical
• Against-the-rule: Steeper curve is horizontal
• Oblique: Steeper curve at an angle

Astigmatism Statistics

• Affects 30-40% of people
• Often occurs with myopia or hyperopia
• Usually present from birth
• Generally stable in adults

Symptoms of Astigmatism

• Blurry vision at all distances
• Eyestrain and headaches
• Difficulty with night driving
• Squinting to see clearly
• Distorted or "stretched" images

How LASIK Corrects Astigmatism

The laser:

• Maps the cornea's irregular shape
• Removes tissue selectively
• Creates a more spherical surface
• Allows light to focus at one point
• Can correct up to 6.00 diopters

Astigmatism and LASIK Success

• Very high success rates
• Wavefront-guided improves precision
• Some may need enhancement
• Most achieve excellent vision