Refractive errors of the eye are relatively common and are seen in around 20 percent of children examined. An inability to focus clearly on objects, a refractive error may occur for more than one reason. The strain on the eyes from a refractive error is known to cause headaches. This has been the cause of some small controversy as many doctors now think that refractive error is often overdiagnosed as the cause of headaches.

Astigmatism may occur either in childhood or adulthood. It is caused by an abnormal curvature of the cornea which causes the focal point of one eye to be mismatched with the other. Objects both up close and at a distance may appear blurry. Headaches from the strain on the eyes from this condition are quite common. Usually this refractive error and its headaches can be corrected with glasses or contact lenses that correct the imbalance.

Hyperopia is most commonly called farsightedness. This refractive error of the eye is usually caused by the axis of the eyeball being too short. The headaches associated with this refractive error are also the result of too much strain being placed on the eyes from an attempt to correct for the imbalance. Eyeglasses and contact lenses are a relatively easy way to correct for the condition and to eliminate the headaches that are associated with this refractive error as you can read from Types of refractive surgery post.

In relation to your eyes, refraction refers to how light waves bend as they pass through your cornea and lens. Your eye’s ability to refract light determines its ability to focus light, which establishes how well you see.

Your eye has a refractive error if it cannot focus an image sharply. Determining the lens prescription needed to correct the error is called a refraction or refraction assessment.

Your eye’s ability to refract light depends on the overall length of the eye and the curvature of the eye’s surface (cornea). If the eye is too long, images mistakenly focused in front of the retina are out of focus when they reach the retina, and you are nearsighted. If the eye is too short, images are not in focus by the time they get to the retina, and you are farsighted. If the cornea is not properly curved, you have astigmatism.