Which term refers to a defect in curvature that causes distorted vision?

The term that refers to a defect in curvature that causes distorted vision is astigmatism. This condition arises when the cornea, which is the front surface of the eye, or the lens inside the eye has an irregular shape. Instead of being perfectly spherical, which allows for light rays to focus evenly on the retina, an astigmatic eye has a more oval shape. This irregular curvature leads to light being focused at multiple points rather than just one, resulting in blurriness or distortion in vision at different distances.

Myopia, while a common refractive error, refers specifically to nearsightedness, where distant objects appear blurry due to light focusing in front of the retina. Tropia describes a type of strabismus, where the eyes are not aligned properly. Accommodation refers to the eye's ability to change its focus from distant to near objects and is not related to curvature defects. Understanding these distinctions is key to recognizing how various optical conditions affect vision.