REFRACTION ERROR Meaning and
Definition
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Refraction error refers to a common vision problem that occurs due to the bending of light as it passes through the eye, resulting in unclear or blurred vision. It is specifically related to the way the eye focuses incoming light rays onto the retina, located at the back of the eye. In a normal eye, light enters the eye through the cornea (the clear front surface of the eye) and then passes through the pupil (the black, circular opening in the center of the iris) before being refracted by the lens and focused onto the retina.
However, in individuals with a refractive error, the shape of the cornea, lens, or eye length may be irregular, causing the light rays to be improperly focused. There are different types of refractive errors, including myopia (nearsightedness), hyperopia (farsightedness), astigmatism, and presbyopia.
Myopia causes nearby objects to be seen clearly while distant objects appear blurry. Hyperopia results in clear distance vision but causes difficulty in focusing on close objects. Astigmatism causes distorted or blurred vision at all distances, and presbyopia occurs with age and causes the inability to focus on close objects.
Refraction errors are typically corrected using eyeglasses, contact lenses, or corrective surgeries like LASIK (Laser-Assisted In Situ Keratomileusis) or PRK (Photorefractive Keratectomy), where the shape of the cornea is altered to improve the focusing capability of the eye. Regular eye examinations are crucial for the early detection and correction of refractive errors, ensuring optimal visual acuity and overall eye health.
Etymology of REFRACTION ERROR
The word "refraction" originates from the Latin word "refractus", which means "broken" or "distorted". It is a combination of the prefix "re-" (indicating a reversal or change) and the verb "frangere" (meaning "to break"). In the context of optics, refraction refers to the bending of light as it passes through different mediums.
The term "refraction error" is commonly used to describe a condition in which the eye does not properly refract or bend incoming light, resulting in visual impairment. The word "error" refers to the deviation or mistake from the normal refractive state of the eye.
