What condition is characterized by the eye's inability to focus light, resulting in blurred vision?

The condition characterized by the eye's inability to focus light, resulting in blurred vision, is astigmatism. This refractive error occurs when the cornea is irregularly shaped or the lens within the eye has mismatched curves. As a result, light entering the eye is not evenly focused on the retina, causing distorted or blurred vision at all distances.

In contrast, hyperopia, also known as farsightedness, occurs when distant objects can be seen more clearly than nearby ones because the eye is shorter than normal or the cornea has too little curvature. Myopia, or nearsightedness, is when nearby objects are seen clearly, but distant objects appear blurred due to the eye being longer than normal or the cornea too curved. Presbyopia is a condition associated with aging where the eye gradually loses its ability to focus on nearby objects, typically starting around the age of 40.

In summary, astigmatism specifically refers to the distortion of vision due to an irregular shape of the eye's lens or cornea, leading to a general blurriness, making it the correct choice for this question.