Anisometropia is a condition where the two eyes have different refractive powers. One eye might be nearsighted while the other is farsighted, or one eye could have significantly better vision than the other. This is a particular concern for newborns and young children, as it can result in impaired vision in one eye. When anisometropia is pronounced, the brain struggles to merge the differing images from the eyes. Consequently, it favors the image from one eye over the other, eventually ignoring the second eye's input. Over time, this can cause the brain to lose the ability to process images from the neglected eye. The term anisometropia comes from Greek, consisting of four parts: an- (not) + -iso- (equal) + -metr- (measure) + -opia (vision), meaning that the measure of vision is unequal. In contrast, isometropia refers to a condition where both eyes have equal refractive power.