Which eye condition is defined by an irregular curvature of the cornea, causing distorted vision at multiple distances?

Which eye condition is defined by an irregular curvature of the cornea, causing distorted vision at multiple distances?

• A. Myopia
• B. Hyperopia
• C. Astigmatism
• D. Presbyopia

Answer: (C)

An irregular corneal curvature changes how light is bent as it enters the eye. If the cornea isn’t evenly curved, light rays are refracted differently in different meridians, so they don’t focus to a single point on the retina. This creates multiple focal points and blurred or distorted vision at various distances. That combination—uneven corneal curvature leading to blurred vision across near and far tasks—is the hallmark of astigmatism. In contrast, myopia means the focal point falls in front of the retina (blurry distance vision more than near), hyperopia means the focal point falls behind the retina (near vision is blurred), and presbyopia is age-related difficulty focusing on close objects due to reduced lens accommodation. Astigmatism is typically corrected with lenses that have cylindrical power or with procedures that reshape the cornea to straighten the refractive surface.

An irregular corneal curvature changes how light is bent as it enters the eye. If the cornea isn’t evenly curved, light rays are refracted differently in different meridians, so they don’t focus to a single point on the retina. This creates multiple focal points and blurred or distorted vision at various distances. That combination—uneven corneal curvature leading to blurred vision across near and far tasks—is the hallmark of astigmatism. In contrast, myopia means the focal point falls in front of the retina (blurry distance vision more than near), hyperopia means the focal point falls behind the retina (near vision is blurred), and presbyopia is age-related difficulty focusing on close objects due to reduced lens accommodation. Astigmatism is typically corrected with lenses that have cylindrical power or with procedures that reshape the cornea to straighten the refractive surface.