What condition involves a cone-shaped bulging of the cornea leading to distortion and blurriness?

The correct answer is keratoconus, a condition characterized by the progressive thinning and distortion of the cornea, which causes it to bulge into a cone shape. This alteration in the cornea's curvature leads to significant visual disturbances, including distortion and blurred vision.

As keratoconus progresses, the irregular shape of the cornea affects how light enters the eye, resulting in an inability to focus light evenly on the retina. Patients often experience increased sensitivity to light and glare in addition to the blurriness caused by the distorted image.

Unlike keratoconus, cataracts involve clouding of the lens inside the eye, leading to blurred vision, but they do not affect the shape of the cornea. Astigmatism also results in blurred vision, yet it is typically caused by an irregular curvature of the cornea or lens, rather than thinning and bulging. Glaucoma refers to a group of eye conditions that damage the optic nerve, often associated with increased intraocular pressure, and does not specifically involve corneal shape changes. Each of these conditions presents different challenges and treatment options, making it essential to understand their distinct characteristics.