What is a common symptom of keratoconus?

Keratoconus is a progressive eye disorder that affects the structure of the cornea, causing it to thin and bulge outward into a cone shape. This alteration in the corneal shape leads to significant visual impairment. One of the hallmark symptoms of keratoconus is major blurring and distortion of vision. As the cornea becomes increasingly irregular, the light entering the eye does not focus evenly on the retina, resulting in visual challenges such as distorted images and fluctuating vision quality.

The other options do not accurately represent typical keratoconus symptoms. Improved vision with glasses usually occurs for individuals with common refractive errors, but the irregular shape of the cornea in keratoconus makes standard corrective lenses less effective over time. Clear vision is not a symptom associated with keratoconus since the condition typically leads to visual distortion rather than clarity. Temporary flashes of light, while they may occur in other eye conditions, are not characteristic of keratoconus. These insights clarify why major blurring and distortion of vision is indeed a common symptom of this condition.