What term describes a refractive error where the eye does not focus light evenly on the retina?

The term that describes a refractive error where the eye does not focus light evenly on the retina is ametropia. Ametropia encompasses various types of refractive errors, including myopia (nearsightedness), hyperopia (farsightedness), and astigmatism. It is characterized by an inability of the eye to focus light precisely on the retina, which can lead to blurred vision. This condition arises when either the shape of the eye, the curvature of the cornea, or the lens's ability to refract light is abnormal.

While anisometropia refers to a condition where there is a significant difference in the refractive power between the two eyes, it is a specific type of ametropia. Asthenopia is related to eye strain or fatigue, often associated with prolonged visual tasks, while esotropia is a type of strabismus where one eye turns inward. These conditions are related to visual function but do not directly describe a general refractive error affecting how light focuses on the retina like ametropia does.