Which eye condition is caused by uneven curvatures of the cornea causing improper focus?

Which eye condition is caused by uneven curvatures of the cornea causing improper focus?

• A. Astigmatism
• B. Near-sighted
• C. Far-sighted
• D. Plane mirror

Answer: (A)

Uneven curvatures of the cornea change how light is bent as it enters the eye. Normally the cornea curves smoothly so light from a single point focuses to one spot on the retina. When the cornea has different curvatures in different directions, light rays are bent by different amounts along different lines, so they don’t all meet at one point. This makes the image appear blurred or distorted because parts of the image are focused differently. This condition is astigmatism. It’s different from nearsightedness or farsightedness, which involve overall focus distance, not multiple focal points caused by an irregular corneal shape. Plane mirrors aren’t involved in how the eye focuses light. Astigmatism can be corrected with glasses or contact lenses that have cylindrical power to balance the differing focal distances.

Uneven curvatures of the cornea change how light is bent as it enters the eye. Normally the cornea curves smoothly so light from a single point focuses to one spot on the retina. When the cornea has different curvatures in different directions, light rays are bent by different amounts along different lines, so they don’t all meet at one point. This makes the image appear blurred or distorted because parts of the image are focused differently. This condition is astigmatism. It’s different from nearsightedness or farsightedness, which involve overall focus distance, not multiple focal points caused by an irregular corneal shape. Plane mirrors aren’t involved in how the eye focuses light. Astigmatism can be corrected with glasses or contact lenses that have cylindrical power to balance the differing focal distances.