Far-sightedness Far-sightedness Far-sightedness, also known as hyperopia, is a condition of the eye in which light is focused behind, instead of on, the retina. This results in close objects appearing blurry, while far objects may appear normal. As the condition worsens, objects at all distances may be blurry. Other symptoms may include headaches and eye strain. People may also experience accommodative dysfunction, binocular dysfunction, amblyopia, and strabismus. The cause is an imperfection of the eyes. Often it occurs when the eyeball is too short, or the lens or cornea is misshapen. Risk factors include a family history of the condition, diabetes,
Anomaly matching condition Anomaly matching condition In quantum field theory, the anomaly matching condition by Gerard 't Hooft states that the calculation of any chiral anomaly for the flavor symmetry must not depend on what scale is chosen for the calculation if it is done by using the degrees of freedom of the theory at some energy scale. It is also known as the 't Hooft condition and the 't Hooft UV-IR anomaly matching condition. There are two closely related but different types of obstructions to formulating a quantum field theory that are both called anomalies: chiral, or "Adler-Bell-Jackiw" anomalies, and 't Hooft