Question Detail
Question
What optical defect is characterized by a non-spherical or distorted cornea, causing horizontal and vertical lines to be imaged in different planes?
Correct Answer
Option D is the correct answer.
Detailed Explanation
The document defines Astigmatism as a defect 'in which the surface of the cornea is not spherical but has a somewhat distorted shape. As a result, horizontal lines may be imaged in a different plane from vertical lines.'
Hint
This defect involves different planes of focus for different orientations.